Journal of Functional Biomaterials

1342 KiB

Open AccessArticle

Influence of Implant Surface Topography on Primary Stability in a Standardized Osteoporosis Rabbit Model Study

by Hiroshi Oue, Kazuya Doi, Yoshifumi Oki, Yusuke Makihara, Takayasu Kubo, Vittoria Perrotti, Adriano Piattelli, Yasumasa Akagawa and Kazuhiro Tsuga

J. Funct. Biomater. 2015, 6(1), 143-152; https://doi.org/10.3390/jfb6010143 - 18 Mar 2015

Cited by 20 | Viewed by 6355

Abstract

Evaluating primary stability is important to predict the prognosis of dental implant treatment. Primary stability is decreased in a low bone density site such as osteoporosis. However, it is difficult to apply in small animal and the effect of the different implant surface [...] Read more.

Evaluating primary stability is important to predict the prognosis of dental implant treatment. Primary stability is decreased in a low bone density site such as osteoporosis. However, it is difficult to apply in small animal and the effect of the different implant surface topography for the primary stability at low bone density site has not yet fully been investigated. The purpose of the present study was to evaluate the influence of implant surface topography on primary stability in a standardized osteoporosis animal model. Six rabbits underwent ovariectomy and administrated glucocorticoid to induce an osteoporosis model. Sham-operations were performed in additional six rabbits. Implants with machined or oxidized-surfaces were inserted into the femur epiphyses and insertion torque (IT) and implant stability quotient (ISQ) were measured. In sham model, the IT and ISQ did not differ significantly between the both implant. However, the IT value of oxidized-surface implant was significantly higher than that of the machined implant in the osteoporosis model. Meanwhile, ISQ did not significantly differ between the machined and oxidized-surfaced implants. In conclusion, the IT of implants is higher with rough than with smooth surfaces but that there are no differences in ISQ value between different surfaces in a standardized osteoporosis bone reduced rabbit model. Full article

(This article belongs to the Special Issue Feature Papers)

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Open AccessReview

RETRACTED: Chitin, Chitosan, and Its Derivatives for Wound Healing: Old and New Materials

by Kazuo Azuma, Ryotaro Izumi, Tomohiro Osaki, Shinsuke Ifuku, Minoru Morimoto, Hiroyuki Saimoto, Saburo Minami and Yoshiharu Okamoto

J. Funct. Biomater. 2015, 6(1), 104-142; https://doi.org/10.3390/jfb6010104 - 13 Mar 2015

Cited by 230 | Viewed by 23846 | Retraction

Abstract

Chitin (β-(1-4)-poly-N-acetyl-D-glucosamine) is widely distributed in nature and is the second most abundant polysaccharide after cellulose. It is often converted to its more deacetylated derivative, chitosan. Previously, many reports have indicated the accelerating effects of chitin, chitosan, and its derivatives on [...] Read more.

Chitin (β-(1-4)-poly-N-acetyl-D-glucosamine) is widely distributed in nature and is the second most abundant polysaccharide after cellulose. It is often converted to its more deacetylated derivative, chitosan. Previously, many reports have indicated the accelerating effects of chitin, chitosan, and its derivatives on wound healing. More recently, chemically modified or nano-fibrous chitin and chitosan have been developed, and their effects on wound healing have been evaluated. In this review, the studies on the wound-healing effects of chitin, chitosan, and its derivatives are summarized. Moreover, the development of adhesive-based chitin and chitosan are also described. The evidence indicates that chitin, chitosan, and its derivatives are beneficial for the wound healing process. More recently, it is also indicate that some nano-based materials from chitin and chitosan are beneficial than chitin and chitosan for wound healing. Clinical applications of nano-based chitin and chitosan are also expected. Full article

(This article belongs to the Special Issue Biomedical Applications of Chitin and Chitosan)

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Open AccessReview

Modulation of the Tumor Microenvironment for Cancer Treatment: A Biomaterials Approach

by Isaac M. Adjei and Sharma Blanka

J. Funct. Biomater. 2015, 6(1), 81-103; https://doi.org/10.3390/jfb6010081 - 17 Feb 2015

Cited by 73 | Viewed by 12684

Abstract

Tumors are complex tissues that consist of stromal cells, such as fibroblasts, immune cells and mesenchymal stem cells, as well as non-cellular components, in addition to neoplastic cells. Increasingly, there is evidence to suggest that these non-neoplastic cell components support cancer initiation, progression [...] Read more.

Tumors are complex tissues that consist of stromal cells, such as fibroblasts, immune cells and mesenchymal stem cells, as well as non-cellular components, in addition to neoplastic cells. Increasingly, there is evidence to suggest that these non-neoplastic cell components support cancer initiation, progression and metastasis and that their ablation or reprogramming can inhibit tumor growth. Our understanding of the activities of different parts of the tumor stroma in advancing cancer has been improved by the use of scaffold and matrix-based 3D systems originally developed for regenerative medicine. Additionally, drug delivery systems made from synthetic and natural biomaterials deliver drugs to kill stromal cells or reprogram the microenvironment for tumor inhibition. In this article, we review the impact of 3D tumor models in increasing our understanding of tumorigenesis. We also discuss how different drug delivery systems aid in the reprogramming of tumor stroma for cancer treatment. Full article

(This article belongs to the Special Issue Biomaterials Approaches for Cancer Research)

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Open AccessEditorial

Ocular Tissue Engineering: Current and Future Directions

by D. Karamichos

J. Funct. Biomater. 2015, 6(1), 77-80; https://doi.org/10.3390/jfb6010077 - 17 Feb 2015

Cited by 31 | Viewed by 6946

Abstract

Tissue engineering (TE) is a concept that was first emerged in the early 1990s to provide solutions to severe injured tissues and/or organs [1]. The dream was to be able to restore and replace the damaged tissue with an engineered version which would [...] Read more.

Tissue engineering (TE) is a concept that was first emerged in the early 1990s to provide solutions to severe injured tissues and/or organs [1]. The dream was to be able to restore and replace the damaged tissue with an engineered version which would ultimately help overcome problems such as donor shortages, graft rejections, and inflammatory responses following transplantation. While an incredible amount of progress has been made, suggesting that TE concept is viable, we are still not able to overcome major obstacles. In TE, there are two main strategies that researchers have adopted: (1) cell-based, where cells are been manipulated to create their own environment before transplanted to the host, and (2) scaffold-based, where an extracellular matrix is created to mimic in vivo structures. TE approaches for ocular tissues are available and have indeed come a long way, over the last decades; however more clinically relevant ocular tissue substitutes are needed. Figure 1 highlights the importance of TE in ocular applications and indicates the avenues available based on each tissue.[...] Full article

(This article belongs to the Special Issue Ocular Tissue Engineering)

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2541 KiB

Open AccessArticle

Cleaning Effectiveness of Three NiTi Rotary Instruments: A Focus on Biomaterial Properties

by Claudio Poggio, Alberto Dagna, Marco Chiesa, Riccardo Beltrami and Stefano Bianchi

J. Funct. Biomater. 2015, 6(1), 66-76; https://doi.org/10.3390/jfb6010066 - 16 Feb 2015

Cited by 16 | Viewed by 7913

Abstract

Nickel-titanium (NiTi) instruments are commonly used for shaping the root canal system in endodontic practice.They are more flexible and have better cutting efficiency than conventional stainless steel files. The superelasticity of NiTi rotary files allows the clinicians to produce the desirable tapered [...] Read more.

Nickel-titanium (NiTi) instruments are commonly used for shaping the root canal system in endodontic practice.They are more flexible and have better cutting efficiency than conventional stainless steel files. The superelasticity of NiTi rotary files allows the clinicians to produce the desirable tapered root canal form with a reduced tendency to canal transportation and instrument fracture. HyFlex CM instruments are new NiTi rotary instruments with shape memory produced by an innovative methodology (patent pending) that uses a complex heating and cooling treatment that controls the material’s memory. The aim of the present study was to compare the cleaning efficacy of two conventional (Mtwo, Revo-S) Ni-Ti rotary instruments with HyFlex CM. 30 single-rooted freshly extracted teeth were divided into three groups. Root canals were shaped with three NiTi instruments (Mtwo, Revo-S and HyFlex CM) using 5.25% NaOCl and 17% EDTA solutions. Specimens were fractured longitudinally and prepared for SEM analysis at standard magnification of 1000×. The presence/absence of debris smear layer and the presence/absence of smear layer at coronal, middle, and apical third of each canal were evaluated using a 5-step scale for scores. Numeric data were analyzed using Kruskall-Wallis and Mann-Whitney U statistical tests and significance was predetermined at P < 0.05. This study revealed significant differences among the various groups. Despite some minor differences, all instruments removed smear layer and debris produced during instrumentation. HyFlex CM seem to be not so effective in promoting cleanliness of root canal walls and in removing smear layer from dentine if compared to Mtwo and Revo-S. Full article

(This article belongs to the Special Issue Biomedical Applications of Shape Memory Alloys)

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561 KiB

Open AccessReview

Tissue Engineering the Cornea: The Evolution of RAFT

by Hannah J. Levis, Alvena K. Kureshi, Isobel Massie, Louise Morgan, Amanda J. Vernon and Julie T. Daniels

J. Funct. Biomater. 2015, 6(1), 50-65; https://doi.org/10.3390/jfb6010050 - 22 Jan 2015

Cited by 50 | Viewed by 9427

Abstract

Corneal blindness affects over 10 million people worldwide and current treatment strategies often involve replacement of the defective layer with healthy tissue. Due to a worldwide donor cornea shortage and the absence of suitable biological scaffolds, recent research has focused on the development [...] Read more.

Corneal blindness affects over 10 million people worldwide and current treatment strategies often involve replacement of the defective layer with healthy tissue. Due to a worldwide donor cornea shortage and the absence of suitable biological scaffolds, recent research has focused on the development of tissue engineering techniques to create alternative therapies. This review will detail how we have refined the simple engineering technique of plastic compression of collagen to a process we now call Real Architecture for 3D Tissues (RAFT). The RAFT production process has been standardised, and steps have been taken to consider Good Manufacturing Practice compliance. The evolution of this process has allowed us to create biomimetic epithelial and endothelial tissue equivalents suitable for transplantation and ideal for studying cell-cell interactions in vitro. Full article

(This article belongs to the Special Issue Corneal Disease and Biomaterials)

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Open AccessReview

Anticancer and Anti-Inflammatory Properties of Chitin and Chitosan Oligosaccharides

by Kazuo Azuma, Tomohiro Osaki, Saburo Minami and Yoshiharu Okamoto

J. Funct. Biomater. 2015, 6(1), 33-49; https://doi.org/10.3390/jfb6010033 - 14 Jan 2015

Cited by 209 | Viewed by 17077

Abstract

Previous reports indicate that N-acetyl-d-glucosamine oligomers (chitin oligosaccharide; NACOS) and d-glucosamine oligomers (chitosan oligosaccharide; COS) have various biological activities, especially against cancer and inflammation. In this review, we have summarized the findings of previous investigations that have focused on anticancer or anti-inflammatory [...] Read more.

Previous reports indicate that N-acetyl-d-glucosamine oligomers (chitin oligosaccharide; NACOS) and d-glucosamine oligomers (chitosan oligosaccharide; COS) have various biological activities, especially against cancer and inflammation. In this review, we have summarized the findings of previous investigations that have focused on anticancer or anti-inflammatory properties of NACOS and COS. Moreover, we have introduced recent evaluation of NACOS and COS as functional foods against cancer and inflammatory disease. Full article

(This article belongs to the Special Issue Biomedical Applications of Chitin and Chitosan)

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5502 KiB

Open AccessArticle

Poly(vinyl alcohol)/gelatin Hydrogels Cultured with HepG2 Cells as a 3D Model of Hepatocellular Carcinoma: A Morphological Study

by Stefania Moscato, Francesca Ronca, Daniela Campani and Serena Danti

J. Funct. Biomater. 2015, 6(1), 16-32; https://doi.org/10.3390/jfb6010016 - 13 Jan 2015

Cited by 37 | Viewed by 8791

Abstract

It has been demonstrated that three-dimensional (3D) cell culture models represent fundamental tools for the comprehension of cellular phenomena both for normal and cancerous tissues. Indeed, the microenvironment affects the cellular behavior as well as the response to drugs. In this study, we [...] Read more.

It has been demonstrated that three-dimensional (3D) cell culture models represent fundamental tools for the comprehension of cellular phenomena both for normal and cancerous tissues. Indeed, the microenvironment affects the cellular behavior as well as the response to drugs. In this study, we performed a morphological analysis on a hepatocarcinoma cell line, HepG2, grown for 24 days inside a bioartificial hydrogel composed of poly(vinyl alcohol) (PVA) and gelatin (G) to model a hepatocellular carcinoma (HCC) in 3D. Morphological features of PVA/G hydrogels were investigated, resulting to mimic the trabecular structure of liver parenchyma. A histologic analysis comparing the 3D models with HepG2 cell monolayers and tumor specimens was performed. In the 3D setting, HepG2 cells were viable and formed large cellular aggregates showing different morphotypes with zonal distribution. Furthermore, β-actin and α5β1 integrin revealed a morphotype-related expression; in particular, the frontline cells were characterized by a strong immunopositivity on a side border of their membrane, thus suggesting the formation of lamellipodia-like structures apt for migration. Based on these results, we propose PVA/G hydrogels as valuable substrates to develop a long term 3D HCC model that can be used to investigate important aspects of tumor biology related to migration phenomena. Full article

(This article belongs to the Special Issue Biomaterials Approaches for Cancer Research)

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Open AccessEditorial

Acknowledgement to Reviewers of the Journal of Functional Biomaterials in 2014

by JFB Editorial Office

J. Funct. Biomater. 2015, 6(1), 14-15; https://doi.org/10.3390/jfb6010014 - 9 Jan 2015

Viewed by 3627

Abstract

The editors of the Journal of Functional Biomaterials would like to express their sincere gratitude to the following reviewers for assessing manuscripts in 2014:[...] Full article

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Open AccessArticle

Caffeic Acid-PLGA Conjugate to Design Protein Drug Delivery Systems Stable to Irradiation

by Francesca Selmin, Francesco Puoci, Ortensia I. Parisi, Silvia Franzé, Umberto M. Musazzi and Francesco Cilurzo

J. Funct. Biomater. 2015, 6(1), 1-13; https://doi.org/10.3390/jfb6010001 - 5 Jan 2015

Cited by 7 | Viewed by 5833

Abstract

This work reports the feasibility of caffeic acid grafted PLGA (g-CA-PLGA) to design biodegradable sterile microspheres for the delivery of proteins. Ovalbumin (OVA) was selected as model compound because of its sensitiveness of γ-radiation. The adopted grafting procedure allowed us to obtain a [...] Read more.

This work reports the feasibility of caffeic acid grafted PLGA (g-CA-PLGA) to design biodegradable sterile microspheres for the delivery of proteins. Ovalbumin (OVA) was selected as model compound because of its sensitiveness of γ-radiation. The adopted grafting procedure allowed us to obtain a material with good free radical scavenging properties, without a significant modification of M_w and T_g of the starting PLGA (M_w_PLGA = 26.3 ± 1.3 kDa vs. M_w_g-CA-PLGA = 22.8 ± 0.7 kDa; T_g_PLGA = 47.7 ± 0.8 °C vs. T_g_g-CA-PLGA = 47.4 ± 0.2 °C). By using a W₁/O/W₂ technique, g-CA-PLGA improved the encapsulation efficiency (EE), suggesting that the presence of caffeic residues improved the compatibility between components (EE_PLGA = 35.0% ± 0.7% vs. EE_g-CA-PLGA = 95.6% ± 2.7%). Microspheres particle size distribution ranged from 15 to 50 µm. The zeta-potential values of placebo and loaded microspheres were −25 mV and −15 mV, respectively. The irradiation of g-CA-PLGA at the dose of 25 kGy caused a less than 1% variation of M_w and the degradation patterns of the non-irradiated and irradiated microspheres were superimposable. The OVA content in g-CA-PLGA microspheres decreased to a lower extent with respect to PLGA microspheres. These results suggest that g-CA-PLGA is a promising biodegradable material to microencapsulate biological drugs. Full article

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J. Funct. Biomater., Volume 6, Issue 1 (March 2015) – 10 articles , Pages 1-152

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