Polymers

Editorial

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5 pages, 195 KiB

Open AccessEditorial

Advanced Polymeric Scaffolds for Stem Cell Engineering and Regenerative Medicine

by João Carlos Silva and Frederico Castelo Ferreira

Polymers 2024, 16(18), 2667; https://doi.org/10.3390/polym16182667 - 22 Sep 2024

Cited by 1 | Viewed by 3823

Abstract

Polymeric scaffolds play a pivotal role in tissue engineering (TE) and regenerative medicine strategies, as they offer the possibility to closely mimic the architectural features of the native tissues’ extracellular matrix (ECM) and support cell performance both in vitro and in vivo, creating [...] Read more.

Polymeric scaffolds play a pivotal role in tissue engineering (TE) and regenerative medicine strategies, as they offer the possibility to closely mimic the architectural features of the native tissues’ extracellular matrix (ECM) and support cell performance both in vitro and in vivo, creating a favourable regenerative microenvironment [...] Full article

(This article belongs to the Special Issue Advanced Polymeric Scaffolds for Stem Cell Engineering and Regenerative Medicine)

Research

Jump to: Editorial, Review

14 pages, 5617 KiB

Open AccessArticle

Selection and Optimization of a Bioink Based on PANC-1- Plasma/Alginate/Methylcellulose for Pancreatic Tumour Modelling

by Cristina Banda Sánchez, Nieves Cubo Mateo, Laura Saldaña, Alba Valdivieso, Julie Earl, Itziar González Gómez and Luis M. Rodríguez-Lorenzo

Polymers 2023, 15(15), 3196; https://doi.org/10.3390/polym15153196 - 27 Jul 2023

Cited by 8 | Viewed by 1794

Abstract

3D bioprinting involves using bioinks that combine biological and synthetic materials. The selection of the most appropriate cell-material combination for a specific application is complex, and there is a lack of consensus on the optimal conditions required. Plasma-loaded alginate and alginate/methylcellulose (Alg/MC) inks [...] Read more.

3D bioprinting involves using bioinks that combine biological and synthetic materials. The selection of the most appropriate cell-material combination for a specific application is complex, and there is a lack of consensus on the optimal conditions required. Plasma-loaded alginate and alginate/methylcellulose (Alg/MC) inks were chosen to study their viscoelastic behaviour, degree of recovery, gelation kinetics, and cell survival after printing. Selected inks showed a shear thinning behavior from shear rates as low as 0.2 s^−1, and the ink composed of 3% w/v SA and 9% w/v MC was the only one showing a successful stacking and 96% recovery capacity. A 0.5 × 10⁶ PANC-1 cell-laden bioink was extruded with an Inkredible 3D printer (Cellink) through a D = 410 μm tip conical nozzle into 6-well culture plates. Cylindrical constructs were printed and crosslinked with CaCl₂. Bioinks suffered a 1.845 Pa maximum pressure at the tip that was not deleterious for cellular viability. Cell aggregates can be appreciated for the cut total length observed in confocal microscopy, indicating a good proliferation rate at different heights of the construct, and suggesting the viability of the selected bioink PANC-1/P-Alg₃/MC₉ for building up three-dimensional bioprinted pancreatic tumor constructs. Full article

(This article belongs to the Special Issue Advanced Polymeric Scaffolds for Stem Cell Engineering and Regenerative Medicine)

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25 pages, 5903 KiB

Open AccessArticle

A Novel Approach for Design and Manufacturing of Curvature-Featuring Scaffolds for Osteochondral Repair

by Pedro Marcelino, João Carlos Silva, Carla S. Moura, João Meneses, Rachel Cordeiro, Nuno Alves, Paula Pascoal-Faria and Frederico Castelo Ferreira

Polymers 2023, 15(9), 2129; https://doi.org/10.3390/polym15092129 - 29 Apr 2023

Cited by 3 | Viewed by 2212

Abstract

Osteochondral (OC) defects affect both articular cartilage and the underlying subchondral bone. Due to limitations in the cartilage tissue’s self-healing capabilities, OC defects exhibit a degenerative progression to which current therapies have not yet found a suitable long-term solution. Tissue engineering (TE) strategies [...] Read more.

Osteochondral (OC) defects affect both articular cartilage and the underlying subchondral bone. Due to limitations in the cartilage tissue’s self-healing capabilities, OC defects exhibit a degenerative progression to which current therapies have not yet found a suitable long-term solution. Tissue engineering (TE) strategies aim to fabricate tissue substitutes that recreate natural tissue features to offer better alternatives to the existing inefficient treatments. Scaffold design is a key element in providing appropriate structures for tissue growth and maturation. This study presents a novel method for designing scaffolds with a mathematically defined curvature, based on the geometry of a sphere, to obtain TE constructs mimicking native OC tissue shape. The lower the designed radius, the more curved the scaffold obtained. The printability of the scaffolds using fused filament fabrication (FFF) was evaluated. For the case-study scaffold size (20.1 mm × 20.1 mm projected dimensions), a limit sphere radius of 17.064 mm was determined to ensure printability feasibility, as confirmed by scanning electron microscopy (SEM) and micro-computed tomography (μ-CT) analysis. The FFF method proved suitable to reproduce the curved designs, showing good shape fidelity and replicating the expected variation in porosity. Additionally, the mechanical behavior was evaluated experimentally and by numerical modelling. Experimentally, curved scaffolds showed strength comparable to conventional orthogonal scaffolds, and finite element analysis was used to identify the scaffold regions more susceptible to higher loads. Full article

(This article belongs to the Special Issue Advanced Polymeric Scaffolds for Stem Cell Engineering and Regenerative Medicine)

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14 pages, 2496 KiB

Open AccessArticle

Poly(ε-caprolactone)-poly(ethylene glycol) Tri-Block Copolymer as Quercetin Delivery System for Human Colorectal Carcinoma Cells: Synthesis, Characterization and In Vitro Study

by Nancy Ferrentino, Maria Preziosa Romano, Silvia Zappavigna, Marianna Abate, Vitale Del Vecchio, Dario Romano, Chiara Germinario, Celestino Grifa, Rosanna Filosa and Daniela Pappalardo

Polymers 2023, 15(5), 1179; https://doi.org/10.3390/polym15051179 - 26 Feb 2023

Cited by 10 | Viewed by 2724

Abstract

Quercetin is a hydrophobic molecule with short blood circulation times and instability. The development of a nano-delivery system formulation of quercetin may increase its bioavailability, resulting in greater tumor suppressing effects. Triblock ABA type polycaprolactone-polyethylenglycol- polycaprolactone (PCL-PEG-PCL) copolymers have been synthetized using ring-opening [...] Read more.

Quercetin is a hydrophobic molecule with short blood circulation times and instability. The development of a nano-delivery system formulation of quercetin may increase its bioavailability, resulting in greater tumor suppressing effects. Triblock ABA type polycaprolactone-polyethylenglycol- polycaprolactone (PCL-PEG-PCL) copolymers have been synthetized using ring-opening polymerization of caprolactone from PEG diol. The copolymers were characterized by nuclear magnetic resonance (NMR), diffusion-ordered NMR spectroscopy (DOSY), and gel permeation chromatography (GPC). The triblock copolymers self-assembled in water forming micelles consisting of a core of biodegradable polycaprolactone (PCL) and a corona of polyethylenglycol (PEG). The core-shell PCL-PEG-PCL nanoparticles were able to incorporate quercetin into the core. They were characterized by dynamic light scattering (DLS) and NMR. The cellular uptake efficiency of human colorectal carcinoma cells was quantitatively determined by flow cytometry using nanoparticles loaded with Nile Red as hydrophobic model drug. The cytotoxic effect of quercetin-loaded nanoparticles was evaluated on HCT 116 cells, showing promising results. Full article

(This article belongs to the Special Issue Advanced Polymeric Scaffolds for Stem Cell Engineering and Regenerative Medicine)

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20 pages, 4656 KiB

Open AccessArticle

Cellulose-Based Scaffolds: A Comparative Study for Potential Application in Articular Cartilage

by Rachel Cordeiro, Rui D. Alvites, Ana C. Sousa, Bruna Lopes, Patrícia Sousa, Ana C. Maurício, Nuno Alves and Carla Moura

Polymers 2023, 15(3), 781; https://doi.org/10.3390/polym15030781 - 3 Feb 2023

Cited by 2 | Viewed by 2194

Abstract

Osteoarthritis is a highly prevalent disease worldwide that leads to cartilage loss. Tissue engineering, involving scaffolds, cells, and stimuli, has shown to be a promising strategy for its repair. Thus, this study aims to manufacture and characterise different scaffolds with poly(ε-caprolactone) (PCL) with [...] Read more.

Osteoarthritis is a highly prevalent disease worldwide that leads to cartilage loss. Tissue engineering, involving scaffolds, cells, and stimuli, has shown to be a promising strategy for its repair. Thus, this study aims to manufacture and characterise different scaffolds with poly(ε-caprolactone) (PCL) with commercial cellulose (microcrystalline (McC) and methyl cellulose (MC) or cellulose from agro-industrial residues (corncob (CcC)) and at different percentages, 1%, 2%, and 3%. PCL scaffolds were used as a control. Morphologically, the produced scaffolds presented porosities within the desired for cell incorporation (57% to 65%). When submitted to mechanical tests, the incorporation of cellulose affects the compression resistance of the majority of scaffolds. Regarding tensile strength, McC2% showed the highest values. It was proven that all manufactured scaffolds suffered degradation after 7 days of testing because of enzymatic reactions. This degradation may be due to the dissolution of PCL in the organic solvent. Biological tests revealed that PCL, CcC1%, and McC3% are the best materials to combine with human dental pulp stem/stromal cells. Overall, results suggest that cellulose incorporation in PCL scaffolds promotes cellular adhesion/proliferation. Methyl cellulose scaffolds demonstrated some advantageous compressive properties (closer to native cartilaginous tissue) to proceed to further studies for application in cartilage repair. Full article

(This article belongs to the Special Issue Advanced Polymeric Scaffolds for Stem Cell Engineering and Regenerative Medicine)

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15 pages, 5955 KiB

Open AccessArticle

Electrospun Biodegradable α-Amino Acid-Substituted Poly(organophosphazene) Fiber Mats for Stem Cell Differentiation towards Vascular Smooth Muscle Cells

by Meng Wang, Shigang Lin and Kibret Mequanint

Polymers 2022, 14(8), 1555; https://doi.org/10.3390/polym14081555 - 11 Apr 2022

Cited by 6 | Viewed by 2281

Abstract

Mesenchymal stem cells, derived from human-induced pluripotent stem cells (iPSC), are valuable for generating smooth muscle cells (SMCs) for vascular tissue engineering applications. In this study, we synthesized biodegradable α-amino acid-substituted poly(organophosphazene) polymers and electrospun nano-fibrous scaffolds (~200 nm diameter) to evaluate their [...] Read more.

Mesenchymal stem cells, derived from human-induced pluripotent stem cells (iPSC), are valuable for generating smooth muscle cells (SMCs) for vascular tissue engineering applications. In this study, we synthesized biodegradable α-amino acid-substituted poly(organophosphazene) polymers and electrospun nano-fibrous scaffolds (~200 nm diameter) to evaluate their suitability as a matrix for differentiation of iPSC-derived mesenchymal stem cells (iMSC) into mature contractile SMCs. Both the polymer synthesis approach and the electrospinning parameters were optimized. Three types of cells, namely iMSC, bone marrow derived mesenchymal stem cells (BM-MSC), and primary human coronary artery SMC, attached and spread on the materials. Although L-ascorbic acid (AA) and transforming growth factor-beta 1 (TGF-β1) were able to differentiate iMSC along the smooth muscle lineage, we showed that the electrospun fibrous mats provided material cues for the enhanced differentiation of iMSCs. Differentiation of iMSC to SMC was characterized by increased transcriptional levels of early to late-stage smooth muscle marker proteins on electrospun fibrous mats. Our findings provide a feasible strategy for engineering functional vascular tissues. Full article

(This article belongs to the Special Issue Advanced Polymeric Scaffolds for Stem Cell Engineering and Regenerative Medicine)

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20 pages, 4901 KiB

Open AccessArticle

The Collagen Origin Influences the Degradation Kinetics of Guided Bone Regeneration Membranes

by Marta Vallecillo-Rivas, Manuel Toledano-Osorio, Cristina Vallecillo, Manuel Toledano and Raquel Osorio

Polymers 2021, 13(17), 3007; https://doi.org/10.3390/polym13173007 - 5 Sep 2021

Cited by 25 | Viewed by 3252

Abstract

Collagen membranes are currently the most widely used membranes for guided bone regeneration; however, their rapid degradation kinetics means that the barrier function may not remain for enough time to permit tissue regeneration to happen. The origin of collagen may have an important [...] Read more.

Collagen membranes are currently the most widely used membranes for guided bone regeneration; however, their rapid degradation kinetics means that the barrier function may not remain for enough time to permit tissue regeneration to happen. The origin of collagen may have an important effect on the resistance to degradation. The aim of this study was to investigate the biodegradation pattern of five collagen membranes from different origins: Biocollagen, Heart, Evolution X-fine, CopiOs and Parasorb Resodont. Membranes samples were submitted to different degradation tests: (1) hydrolytic degradation in phosphate buffer saline solution, (2) bacterial collagenase from Clostridium histolyticum solution, and (3) enzyme resistance using a 0.25% porcine trypsin solution. Immersion periods from 1 up to 50 days were performed. At each time point, thickness and weight measurements were performed with a digital caliper and an analytic microbalance, respectively. ANOVA and Student–Newman–Keuls tests were used for comparisons (p < 0.05). Differences between time-points within the same membranes and solutions were assessed by pair-wise comparisons (p < 0.001). The Evolution X-fine collagen membrane from porcine pericardium attained the highest resistance to all of the degradation tests. Biocollagen and Parasorb Resodont, both from equine origin, experienced the greatest degradation when immersed in PBS, trypsin and C. histolyticum during challenge tests. The bacterial collagenase solution was shown to be the most aggressive testing method. Full article

(This article belongs to the Special Issue Advanced Polymeric Scaffolds for Stem Cell Engineering and Regenerative Medicine)

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22 pages, 10417 KiB

Open AccessArticle

Tissue-Engineered Carotid Artery Interposition Grafts Demonstrate High Primary Patency and Promote Vascular Tissue Regeneration in the Ovine Model

by Larisa V. Antonova, Evgenia O. Krivkina, Viktoriia V. Sevostianova, Andrey V. Mironov, Maria A. Rezvova, Amin R. Shabaev, Vadim O. Tkachenko, Sergey S. Krutitskiy, Mariam Yu. Khanova, Tatiana Yu. Sergeeva, Vera G. Matveeva, Tatiana V. Glushkova, Anton G. Kutikhin, Rinat A. Mukhamadiyarov, Nadezhda S. Deeva, Tatiana N. Akentieva, Maxim Yu. Sinitsky, Elena A. Velikanova and Leonid S. Barbarash

Polymers 2021, 13(16), 2637; https://doi.org/10.3390/polym13162637 - 8 Aug 2021

Cited by 14 | Viewed by 3356

Abstract

Tissue-engineered vascular graft for the reconstruction of small arteries is still an unmet clinical need, despite the fact that a number of promising prototypes have entered preclinical development. Here we test Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)Poly(ε-caprolactone) 4-mm-diameter vascular grafts equipped with vascular endothelial growth factor (VEGF), basic [...] Read more.

Tissue-engineered vascular graft for the reconstruction of small arteries is still an unmet clinical need, despite the fact that a number of promising prototypes have entered preclinical development. Here we test Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)Poly(ε-caprolactone) 4-mm-diameter vascular grafts equipped with vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and stromal cell-derived factor 1α (SDF-1α) and surface coated with heparin and iloprost (PHBV/PCL[VEGF-bFGF-SDF]^Hep/Ilo, n = 8) in a sheep carotid artery interposition model, using biostable vascular prostheses of expanded poly(tetrafluoroethylene) (ePTFE, n = 5) as a control. Primary patency of PHBV/PCL[VEGF-bFGF-SDF]^Hep/Ilo grafts was 62.5% (5/8) at 24 h postimplantation and 50% (4/8) at 18 months postimplantation, while all (5/5) ePTFE conduits were occluded within the 24 h after the surgery. At 18 months postimplantation, PHBV/PCL[VEGF-bFGF-SDF]^Hep/Ilo grafts were completely resorbed and replaced by the vascular tissue. Regenerated arteries displayed a hierarchical three-layer structure similar to the native blood vessels, being fully endothelialised, highly vascularised and populated by vascular smooth muscle cells and macrophages. The most (4/5, 80%) of the regenerated arteries were free of calcifications but suffered from the aneurysmatic dilation. Therefore, biodegradable PHBV/PCL[VEGF-bFGF-SDF]^Hep/Ilo grafts showed better short- and long-term results than bio-stable ePTFE analogues, although these scaffolds must be reinforced for the efficient prevention of aneurysms. Full article

(This article belongs to the Special Issue Advanced Polymeric Scaffolds for Stem Cell Engineering and Regenerative Medicine)

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17 pages, 12292 KiB

Open AccessArticle

The Effect of Adding Modified Chitosan on the Strength Properties of Bacterial Cellulose for Clinical Applications

by Anna Lipovka, Alexey Kharchenko, Andrey Dubovoy, Maxim Filipenko, Vyacheslav Stupak, Alexander Mayorov, Vladislav Fomenko, Pavel Geydt and Daniil Parshin

Polymers 2021, 13(12), 1995; https://doi.org/10.3390/polym13121995 - 18 Jun 2021

Cited by 7 | Viewed by 3027

Abstract

Currently, several materials for the closure of the dura mater (DM) defects are known. However, the long-term results of their usage reveal a number of disadvantages. The use of antibiotics and chitosan is one of the major trends in solving the problems associated [...] Read more.

Currently, several materials for the closure of the dura mater (DM) defects are known. However, the long-term results of their usage reveal a number of disadvantages. The use of antibiotics and chitosan is one of the major trends in solving the problems associated with infectious after-operational complications. This work compares the mechanical properties of samples of bacterial nanocellulose (BNC) impregnated with Novochizol™ and vancomycin with native BNC and preserved and native human DM. An assessment of the possibility of controling the mechanical properties of these materials by changing their thickness has been performed by statistical analysis methods. A total of 80 specimens of comparable samples were investigated. During the analysis, the results obtained, the factor of Novochizol™ addition has provided a statistically significant impact on the strength properties (Fisher Criteria p-value 0.00509 for stress and 0.00112 for deformation). Moreover, a stronger relationship between the thickness of the samples and their ultimate load was shown:

R^{2} = 0.236

for BNC + Novochizol™ + vancomycin, compared to

R^{2} = 0.0405

for native BNC. Using factor analysis, it was possible to show a significant effect of modified chitosan (Novochizol™) on the ultimate stress (p-value = 0.005). Full article

(This article belongs to the Special Issue Advanced Polymeric Scaffolds for Stem Cell Engineering and Regenerative Medicine)

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13 pages, 2775 KiB

Open AccessArticle

Engineering of Optimized Hydrogel Formulations for Cartilage Repair

by Yao Fu, Bram Zoetebier, Sanne Both, Pieter J. Dijkstra and Marcel Karperien

Polymers 2021, 13(9), 1526; https://doi.org/10.3390/polym13091526 - 10 May 2021

Cited by 17 | Viewed by 3746

Abstract

The ideal scaffold for cartilage regeneration is expected to provide adequate mechanical strength, controlled degradability, adhesion, and integration with the surrounding native tissue. As it does this, it mimics natural ECMs functions, which allow for nutrient diffusion and promote cell survival and differentiation. [...] Read more.

The ideal scaffold for cartilage regeneration is expected to provide adequate mechanical strength, controlled degradability, adhesion, and integration with the surrounding native tissue. As it does this, it mimics natural ECMs functions, which allow for nutrient diffusion and promote cell survival and differentiation. Injectable hydrogels based on tyramine (TA)-functionalized hyaluronic acid (HA) and dextran (Dex) are a promising approach for cartilage regeneration. The properties of the hydrogels used in this study were adjusted by varying polymer concentrations and ratios. To investigate the changes in properties and their effects on cellular behavior and cartilage matrix formation, different ratios of HA- and dextran-based hybrid hydrogels at both 5 and 10% w/v were prepared using a designed mold to control generation. The results indicated that the incorporation of chondrocytes in the hydrogels decreased their mechanical properties. However, rheological and compression analysis indicated that 5% w/v hydrogels laden with cells exhibit a significant increase in mechanical properties after 21 days when the constructs are cultured in a chondrogenic differentiation medium. Moreover, compared to the 10% w/v hydrogels, the 5% w/v hybrid hydrogels increased the deposition of the cartilage matrix, especially in constructs with a higher Dex–TA content. These results indicated that 5% w/v hybrid hydrogels with 25% HA–TA and 75% Dex–TA have a high potential as injectable scaffolds for cartilage tissue regeneration. Full article

(This article belongs to the Special Issue Advanced Polymeric Scaffolds for Stem Cell Engineering and Regenerative Medicine)

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14 pages, 2900 KiB

Open AccessArticle

Development of Conductive Gelatine-Methacrylate Inks for Two-Photon Polymerisation

by Paola Sanjuan-Alberte, Jayasheelan Vaithilingam, Jonathan C. Moore, Ricky D. Wildman, Christopher J. Tuck, Morgan R. Alexander, Richard J. M. Hague and Frankie J. Rawson

Polymers 2021, 13(7), 1038; https://doi.org/10.3390/polym13071038 - 26 Mar 2021

Cited by 12 | Viewed by 3945

Abstract

Conductive hydrogel-based materials are attracting considerable interest for bioelectronic applications due to their ability to act as more compatible soft interfaces between biological and electrical systems. Despite significant advances that are being achieved in the manufacture of hydrogels, precise control over the topographies [...] Read more.

Conductive hydrogel-based materials are attracting considerable interest for bioelectronic applications due to their ability to act as more compatible soft interfaces between biological and electrical systems. Despite significant advances that are being achieved in the manufacture of hydrogels, precise control over the topographies and architectures remains challenging. In this work, we present for the first time a strategy to manufacture structures with resolutions in the micro-/nanoscale based on hydrogels with enhanced electrical properties. Gelatine methacrylate (GelMa)-based inks were formulated for two-photon polymerisation (2PP). The electrical properties of this material were improved, compared to pristine GelMa, by dispersion of multi-walled carbon nanotubes (MWCNTs) acting as conductive nanofillers, which was confirmed by electrochemical impedance spectroscopy and cyclic voltammetry. This material was also confirmed to support human induced pluripotent stem cell-derived cardiomyocyte (hPSC-CMs) viability and growth. Ultra-thin film structures of 10 µm thickness and scaffolds were manufactured by 2PP, demonstrating the potential of this method in areas spanning tissue engineering and bioelectronics. Though further developments in the instrumentation are required to manufacture more complex structures, this work presents an innovative approach to the manufacture of conductive hydrogels in extremely low resolution. Full article

(This article belongs to the Special Issue Advanced Polymeric Scaffolds for Stem Cell Engineering and Regenerative Medicine)

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15 pages, 2966 KiB

Open AccessArticle

Triborheological Study under Physiological Conditions of PVA Hydrogel/HA Lubricant as Synthetic System for Soft Tissue Replacement

by Laura C. Duque-Ossa, Gustavo Ruiz-Pulido and Dora I. Medina

Polymers 2021, 13(5), 746; https://doi.org/10.3390/polym13050746 - 28 Feb 2021

Cited by 16 | Viewed by 3376

Abstract

In soft tissue replacement, hydrophilic, flexible, and biocompatible materials are used to reduce wear and coefficient of friction. This study aims to develop and evaluate a solid/liquid triborheological system, polyvinyl alcohol (PVA)/hyaluronic acid (HA), to mimic conditions in human synovial joints. Hydrogel specimens [...] Read more.

In soft tissue replacement, hydrophilic, flexible, and biocompatible materials are used to reduce wear and coefficient of friction. This study aims to develop and evaluate a solid/liquid triborheological system, polyvinyl alcohol (PVA)/hyaluronic acid (HA), to mimic conditions in human synovial joints. Hydrogel specimens prepared via the freeze–thawing technique from a 10% (w/v) PVA aqueous solution were cut into disc shapes (5 ± 0.5 mm thickness). Compression tests of PVA hydrogels presented a Young’s modulus of 2.26 ± 0.52 MPa. Friction tests were performed on a Discovery Hybrid Rheometer DHR-3 under physiological conditions using 4 mg/mL HA solution as lubricant at 37 °C. Contact force was applied between 1 and 20 N, highlighting a coefficient of friction change of 0.11 to 0.31 between lubricated and dry states at 3 N load (angular velocity: 40 rad/s). Thermal behavior was evaluated by differential scanning calorimetry (DSC) in the range of 25–250 °C (5 °C/min rate), showing an endothermic behavior with a melting temperature (Tm) around 231.15 °C. Scanning Electron Microscopy (SEM) tests showed a microporous network that enhanced water content absorption to 82.99 ± 1.5%. Hydrogel achieved solid/liquid lubrication, exhibiting a trapped lubricant pool that supported loads, keeping low coefficient of friction during lubricated tests. In dry tests, interstitial water evaporates continuously without countering sliding movement friction. Full article

(This article belongs to the Special Issue Advanced Polymeric Scaffolds for Stem Cell Engineering and Regenerative Medicine)

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Review

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30 pages, 1385 KiB

Open AccessReview

Designing Electrical Stimulation Platforms for Neural Cell Cultivation Using Poly(aniline): Camphorsulfonic Acid

by Fábio F. F. Garrudo, Robert J. Linhardt, Frederico Castelo Ferreira and Jorge Morgado

Polymers 2023, 15(12), 2674; https://doi.org/10.3390/polym15122674 - 14 Jun 2023

Cited by 3 | Viewed by 2884

Abstract

Electrical stimulation is a powerful strategy to improve the differentiation of neural stem cells into neurons. Such an approach can be implemented, in association with biomaterials and nanotechnology, for the development of new therapies for neurological diseases, including direct cell transplantation and the [...] Read more.

Electrical stimulation is a powerful strategy to improve the differentiation of neural stem cells into neurons. Such an approach can be implemented, in association with biomaterials and nanotechnology, for the development of new therapies for neurological diseases, including direct cell transplantation and the development of platforms for drug screening and disease progression evaluation. Poly(aniline):camphorsulfonic acid (PANI:CSA) is one of the most well-studied electroconductive polymers, capable of directing an externally applied electrical field to neural cells in culture. There are several examples in the literature on the development of PANI:CSA-based scaffolds and platforms for electrical stimulation, but no review has examined the fundamentals and physico-chemical determinants of PANI:CSA for the design of platforms for electrical stimulation. This review evaluates the current literature regarding the application of electrical stimulation to neural cells, specifically reviewing: (1) the fundamentals of bioelectricity and electrical stimulation; (2) the use of PANI:CSA-based systems for electrical stimulation of cell cultures; and (3) the development of scaffolds and setups to support the electrical stimulation of cells. Throughout this work, we critically evaluate the revised literature and provide a steppingstone for the clinical application of the electrical stimulation of cells using electroconductive PANI:CSA platforms/scaffolds. Full article

(This article belongs to the Special Issue Advanced Polymeric Scaffolds for Stem Cell Engineering and Regenerative Medicine)

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21 pages, 2025 KiB

Open AccessReview

A Short Review on Nanostructured Carbon Containing Biopolymer Derived Composites for Tissue Engineering Applications

by Mattia Bartoli, Erik Piatti and Alberto Tagliaferro

Polymers 2023, 15(6), 1567; https://doi.org/10.3390/polym15061567 - 21 Mar 2023

Cited by 3 | Viewed by 1905

Abstract

The development of new scaffolds and materials for tissue engineering is a wide and open realm of material science. Among solutions, the use of biopolymers represents a particularly interesting area of study due to their great chemical complexity that enables creation of specific [...] Read more.

The development of new scaffolds and materials for tissue engineering is a wide and open realm of material science. Among solutions, the use of biopolymers represents a particularly interesting area of study due to their great chemical complexity that enables creation of specific molecular architectures. However, biopolymers do not exhibit the properties required for direct application in tissue repair—such as mechanical and electrical properties—but they do show very attractive chemical functionalities which are difficult to produce through in vitro synthesis. The combination of biopolymers with nanostructured carbon fillers could represent a robust solution to enhance composite properties, producing composites with new and unique features, particularly relating to electronic conduction. In this paper, we provide a review of the field of carbonaceous nanostructure-containing biopolymer composites, limiting our investigation to tissue-engineering applications, and providing a complete overview of the recent and most outstanding achievements. Full article

(This article belongs to the Special Issue Advanced Polymeric Scaffolds for Stem Cell Engineering and Regenerative Medicine)

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25 pages, 1780 KiB

Open AccessReview

A Comprehensive Review of Electrospun Fibers, 3D-Printed Scaffolds, and Hydrogels for Cancer Therapies

by Angelika Zaszczyńska, Beata Niemczyk-Soczynska and Paweł Sajkiewicz

Polymers 2022, 14(23), 5278; https://doi.org/10.3390/polym14235278 - 2 Dec 2022

Cited by 15 | Viewed by 3302

Abstract

Anticancer therapies and regenerative medicine are being developed to destroy tumor cells, as well as remodel, replace, and support injured organs and tissues. Nowadays, a suitable three-dimensional structure of the scaffold and the type of cells used are crucial for creating bio-inspired organs [...] Read more.

Anticancer therapies and regenerative medicine are being developed to destroy tumor cells, as well as remodel, replace, and support injured organs and tissues. Nowadays, a suitable three-dimensional structure of the scaffold and the type of cells used are crucial for creating bio-inspired organs and tissues. The materials used in medicine are made of non-degradable and degradable biomaterials and can serve as drug carriers. Developing flexible and properly targeted drug carrier systems is crucial for tissue engineering, regenerative medicine, and novel cancer treatment strategies. This review is focused on presenting innovative biomaterials, i.e., electrospun nanofibers, 3D-printed scaffolds, and hydrogels as a novel approach for anticancer treatments which are still under development and awaiting thorough optimization. Full article

(This article belongs to the Special Issue Advanced Polymeric Scaffolds for Stem Cell Engineering and Regenerative Medicine)

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11 pages, 1874 KiB

Open AccessReview

A Polymer-Biologic Hybrid Hernia Construct: Review of Data and Early Experiences

by Michael Sawyer, Stephen Ferzoco and George DeNoto III

Polymers 2021, 13(12), 1928; https://doi.org/10.3390/polym13121928 - 10 Jun 2021

Cited by 11 | Viewed by 4813

Abstract

Surgical mesh reinforcement of the human abdominal wall has been found to reduce the chance of recurrence in hernia repairs. While traditionally polymer meshes have been used in hernia repair, alternative mesh options have been engineered to prevent the inflammatory foreign body response [...] Read more.

Surgical mesh reinforcement of the human abdominal wall has been found to reduce the chance of recurrence in hernia repairs. While traditionally polymer meshes have been used in hernia repair, alternative mesh options have been engineered to prevent the inflammatory foreign body response invoked by polymers. A reinforced tissue matrix (RTM) mesh has been developed by embedding a polymer within a decellularized extracellular matrix. This combination has been attributed to the recruitment of host cells, a pro-healing response, and attenuation of the foreign body response. This has been observed to lead to the regeneration of functional tissue within the repair site that is reinforced by the polymer to offload abdominal pressures over time. This manuscript presents the review of OviTex, an RTM, in several types of hernia repair. The authors have found that the use of RTM in hernia repair is effective in preventing foreign body response, promoting wound healing, and providing reinforcement to lower the risk of hernia recurrence. Full article

(This article belongs to the Special Issue Advanced Polymeric Scaffolds for Stem Cell Engineering and Regenerative Medicine)

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33 pages, 2760 KiB

Open AccessReview

Bone Matrix Non-Collagenous Proteins in Tissue Engineering: Creating New Bone by Mimicking the Extracellular Matrix

by Marta S. Carvalho, Joaquim M. S. Cabral, Cláudia L. da Silva and Deepak Vashishth

Polymers 2021, 13(7), 1095; https://doi.org/10.3390/polym13071095 - 30 Mar 2021

Cited by 93 | Viewed by 7959

Abstract

Engineering biomaterials that mimic the extracellular matrix (ECM) of bone is of significant importance since most of the outstanding properties of the bone are due to matrix constitution. Bone ECM is composed of a mineral part comprising hydroxyapatite and of an organic part [...] Read more.

Engineering biomaterials that mimic the extracellular matrix (ECM) of bone is of significant importance since most of the outstanding properties of the bone are due to matrix constitution. Bone ECM is composed of a mineral part comprising hydroxyapatite and of an organic part of primarily collagen with the rest consisting on non-collagenous proteins. Collagen has already been described as critical for bone tissue regeneration; however, little is known about the potential effect of non-collagenous proteins on osteogenic differentiation, even though these proteins were identified some decades ago. Aiming to engineer new bone tissue, peptide-incorporated biomimetic materials have been developed, presenting improved biomaterial performance. These promising results led to ongoing research focused on incorporating non-collagenous proteins from bone matrix to enhance the properties of the scaffolds namely in what concerns cell migration, proliferation, and differentiation, with the ultimate goal of designing novel strategies that mimic the native bone ECM for bone tissue engineering applications. Overall, this review will provide an overview of the several non-collagenous proteins present in bone ECM, their functionality and their recent applications in the bone tissue (including dental) engineering field. Full article

(This article belongs to the Special Issue Advanced Polymeric Scaffolds for Stem Cell Engineering and Regenerative Medicine)

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