International Journal of Molecular Sciences

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4298 KiB

Open AccessArticle

Preparation, Characterization and in Vivo Antimycobacterial Studies of Panchovillin-Chitosan Nanocomposites

by Edward Rwegasila, Egid B. Mubofu, Stephen S. Nyandoro, Paul Erasto and Joan J. E. Munissi

Int. J. Mol. Sci. 2016, 17(10), 1559; https://doi.org/10.3390/ijms17101559 - 27 Sep 2016

Cited by 16 | Viewed by 5752

Abstract

Chitosan (CS, molecular weight 20.2 kDa, degree of deacylation (DD) 73.31%) was successfully obtained by deacetylation of chitin extracted from shrimp (Litopenaeus vannamei) shell wastes. The encapsulation of the bioactive natural product, panchovillin (PANV), isolated from Erythrina schliebenii, on a [...] Read more.

Chitosan (CS, molecular weight 20.2 kDa, degree of deacylation (DD) 73.31%) was successfully obtained by deacetylation of chitin extracted from shrimp (Litopenaeus vannamei) shell wastes. The encapsulation of the bioactive natural product, panchovillin (PANV), isolated from Erythrina schliebenii, on a chitosan-tripolyphosphate (CS/TPP) nano-framework was achieved by ionotropic gelation. Characterization of pure CS, CS/TPP and PANV-CS/TPP nanocomposites was performed by FTIR, SEM and XRD. The molecular weight of chitosan and the thermal stability of the materials were determined by MALDI-TOF-MS and simultaneous thermal analyzer (STA)/DTG, respectively. The respective encapsulation efficiency and loading capacity of the PANV were found to be 70% and 0.36%. The in vitro release studies showed an initial burst of 42% of PANV in the first six hours. This was followed by a slow and sustained release up to 72 h. The in vivo antimycobacterial activities of both PANV and PANV-CS/TPP nanocomposite against Mycobacterium indicus pranii (MIP) using Galleria mellonella larvae as an in vivo infection model are reported in this paper. Full article

(This article belongs to the Special Issue Drug Delivery and Antimicrobial Agents)

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624 KiB

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Antimicrobial Resistance Profile of Planktonic and Biofilm Cells of Staphylococcus aureus and Coagulase-Negative Staphylococci

by Adilson De Oliveira, Valéria Cataneli Pereira, Luiza Pinheiro, Danilo Flávio Moraes Riboli, Katheryne Benini Martins and Maria De Lourdes Ribeiro de Souza da Cunha

Int. J. Mol. Sci. 2016, 17(9), 1423; https://doi.org/10.3390/ijms17091423 - 1 Sep 2016

Cited by 53 | Viewed by 7625

Abstract

The objective of the present study was to determine the antimicrobial resistance profile of planktonic and biofilm cells of Staphylococcus aureus and coagulase-negative staphylococci (CoNS). Two hundred Staphylococcus spp. strains were studied, including 50 S. aureus and 150 CoNS strains (50 S. [...] Read more.

The objective of the present study was to determine the antimicrobial resistance profile of planktonic and biofilm cells of Staphylococcus aureus and coagulase-negative staphylococci (CoNS). Two hundred Staphylococcus spp. strains were studied, including 50 S. aureus and 150 CoNS strains (50 S. epidermidis, 20 S. haemolyticus, 20 S. warneri, 20 S. hominis, 20 S. lugdunensis, and 20 S. saprophyticus). Biofilm formation was investigated by adherence to polystyrene plates. Positive strains were submitted to the broth microdilution method to determine the minimum inhibitory concentration (MIC) for planktonic and biofilm cells and the minimal bactericidal concentration for biofilm cells (MBCB). Forty-nine Staphylococcus spp. strains (14 S. aureus, 13 S. epidermidis, 13 S. saprophyticus, 3 S. haemolyticus, 1 S. hominis, 3 S. warneri, and 2 S. lugdunensis) were biofilm producers. These isolates were evaluated regarding their resistance profile. Determination of planktonic cell MIC identified three (21.4%) S. aureus strains that were resistant to oxacillin and six (42.8%) that were resistant to erythromycin. Among the CoNS, 31 (88.6%) strains were resistant to oxacillin, 14 (40%) to erythromycin, 18 (51.4%) to gentamicin, and 8 (22.8%) to sulfamethoxazole/trimethoprim. None of the planktonic isolates were resistant to vancomycin or linezolid. MICs were 2-, 4-, 8-, and up to 16-fold higher for biofilm cells than for planktonic cells. This observation was more common for vancomycin and erythromycin. The MBCB ranged from 8 to >256 µg/mL for oxacillin, 128 to >128 µg/mL for vancomycin, 256 to >256 µg/mL for erythromycin and gentamicin, >64 µg/mL for linezolid, and 32/608 to >32/608 µg/mL for sulfamethoxazole/trimethoprim. The results showed considerably higher MICs for S. aureus and CoNS biofilm cells compared to planktonic cells. Analysis of MBCM confirmed that even high concentrations of vancomycin were unable to eliminate the biofilms of S. aureus and CoNS species. Linezolid was the most effective drug in inhibiting staphylococci in the biofilm, without an increase in the MIC, when compared to planktonic cells. None of the isolates were resistant to this drug. Full article

(This article belongs to the Special Issue Drug Delivery and Antimicrobial Agents)

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Open AccessArticle

CTHRSSVVC Peptide as a Possible Early Molecular Imaging Target for Atherosclerosis

by Rosemeire A. Silva, Ricardo J. Giordano, Paulo S. Gutierrez, Viviane Z. Rocha, Martina Rudnicki, Patrick Kee, Dulcinéia S. P. Abdalla, Pedro Puech-Leão, Bruno Caramelli, Wadih Arap, Renata Pasqualini, José C. Meneghetti, Fabio L. N. Marques, Menka Khoobchandani, Kattesh V. Katti, Ademar B. Lugão and Jorge Kalil

Int. J. Mol. Sci. 2016, 17(9), 1383; https://doi.org/10.3390/ijms17091383 - 24 Aug 2016

Cited by 10 | Viewed by 6254

Abstract

The purpose of our work was to select phages displaying peptides capable of binding to vascular markers present in human atheroma, and validate their capacity to target the vascular markers in vitro and in low-density lipoprotein receptor knockout (LDLr^−/−) mouse model [...] Read more.

The purpose of our work was to select phages displaying peptides capable of binding to vascular markers present in human atheroma, and validate their capacity to target the vascular markers in vitro and in low-density lipoprotein receptor knockout (LDLr^−/−) mouse model of atherosclerosis. By peptide fingerprinting on human atherosclerotic tissues, we selected and isolated four different peptides sequences, which bind to atherosclerotic lesions and share significant similarity to known human proteins with prominent roles in atherosclerosis. The CTHRSSVVC-phage peptide displayed the strongest reactivity with human carotid atherosclerotic lesions (p < 0.05), when compared to tissues from normal carotid arteries. This peptide sequence shares similarity to a sequence present in the fifth scavenger receptor cysteine-rich (SRCR) domain of CD163, which appeared to bind to CD163, and subsequently, was internalized by macrophages. Moreover, the CTHRSSVVC-phage targets atherosclerotic lesions of a low-density lipoprotein receptor knockout (LDLr^−/−) mouse model of atherosclerosis in vivo to High-Fat diet group versus Control group. Tetraazacyclododecane-1,4,7,10-tetraacetic acid-CTHRSSVVC peptide (DOTA-CTHRSSVVC) was synthesized and labeled with ¹¹¹InCl₃ in >95% yield as determined by high performance liquid chromatography (HPLC), to validate the binding of the peptide in atherosclerotic plaque specimens. The results supported our hypothesis that CTHRSSVVC peptide has a remarkable sequence for the development of theranostics approaches in the treatment of atherosclerosis and other diseases. Full article

(This article belongs to the Special Issue Drug Delivery and Antimicrobial Agents)

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Open AccessArticle

Syngonanthus nitens Bong. (Rhul.)-Loaded Nanostructured System for Vulvovaginal Candidiasis Treatment

by Matheus Aparecido Dos Santos Ramos, Luciani Gaspar De Toledo, Giovana Maria Fioramonti Calixto, Bruna Vidal Bonifácio, Marcelo Gonzaga De Freitas Araújo, Lourdes Campaner Dos Santos, Margarete Teresa Gottardo De Almeida, Marlus Chorilli and Taís Maria Bauab

Int. J. Mol. Sci. 2016, 17(8), 1368; https://doi.org/10.3390/ijms17081368 - 22 Aug 2016

Cited by 48 | Viewed by 6597

Abstract

Herbal-loaded drug delivery nanotechnological systems have been extensively studied recently. The antimicrobial activity of medicinal plants has shown better pharmacological action when such plants are loaded into a drug delivery system than when they are not loaded. Syngonanthus nitens Bong. (Rhul.) belongs to [...] Read more.

Herbal-loaded drug delivery nanotechnological systems have been extensively studied recently. The antimicrobial activity of medicinal plants has shown better pharmacological action when such plants are loaded into a drug delivery system than when they are not loaded. Syngonanthus nitens Bong. (Rhul.) belongs to the Eriocaulaceae family and presents antiulcerogenic, antioxidant, antibacterial, and antifungal activity. The aim of this study was to evaluate the antifungal activity of Syngonanthus nitens (S. nitens) extract that was not loaded (E) or loaded (SE) into a liquid crystal precursor system (S) for the treatment of vulvovaginal candidiasis (VVC) with Candida albicans. The minimal inhibitory concentration (MIC) was determined by the microdilution technique. Additionally, we performed hyphae inhibition and biofilm tests. Finally, experimental candidiasis was evaluated in in vivo models with Wistar female rats. The results showed effective antifungal activity after incorporation into S for all strains tested, with MICs ranging from 31.2 to 62.5 μg/mL. Microscopic observation of SE revealed an absence of filamentous cells 24 h of exposure to a concentration of 31.2 μg/mL. E demonstrated no effective action against biofilms, though SE showed inhibition against biofilms of all strains. In the in vivo experiment, SE was effective in the treatment of infection after only two days of treatment and was more effective than E and amphotericin B. The S. nitens is active against Candida albicans (C. albicans) and the antifungal potential is being enhanced after incorporation into liquid crystal precursor systems (LCPS). These findings represent a promising application of SE in the treatment of VVC. Full article

(This article belongs to the Special Issue Drug Delivery and Antimicrobial Agents)

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Open AccessArticle

Antimicrobial Protein Candidates from the Thermophilic Geobacillus sp. Strain ZGt-1: Production, Proteomics, and Bioinformatics Analysis

by Rawana N. Alkhalili, Katja Bernfur, Tarek Dishisha, Gashaw Mamo, Jenny Schelin, Björn Canbäck, Cecilia Emanuelsson and Rajni Hatti-Kaul

Int. J. Mol. Sci. 2016, 17(8), 1363; https://doi.org/10.3390/ijms17081363 - 19 Aug 2016

Cited by 22 | Viewed by 9843

Abstract

A thermophilic bacterial strain, Geobacillus sp. ZGt-1, isolated from Zara hot spring in Jordan, was capable of inhibiting the growth of the thermophilic G. stearothermophilus and the mesophilic Bacillus subtilis and Salmonella typhimurium on a solid cultivation medium. Antibacterial activity was not observed [...] Read more.

A thermophilic bacterial strain, Geobacillus sp. ZGt-1, isolated from Zara hot spring in Jordan, was capable of inhibiting the growth of the thermophilic G. stearothermophilus and the mesophilic Bacillus subtilis and Salmonella typhimurium on a solid cultivation medium. Antibacterial activity was not observed when ZGt-1 was cultivated in a liquid medium; however, immobilization of the cells in agar beads that were subjected to sequential batch cultivation in the liquid medium at 60 °C showed increasing antibacterial activity up to 14 cycles. The antibacterial activity was lost on protease treatment of the culture supernatant. Concentration of the protein fraction by ammonium sulphate precipitation followed by denaturing polyacrylamide gel electrophoresis separation and analysis of the gel for antibacterial activity against G. stearothermophilus showed a distinct inhibition zone in 15–20 kDa range, suggesting that the active molecule(s) are resistant to denaturation by SDS. Mass spectrometric analysis of the protein bands around the active region resulted in identification of 22 proteins with molecular weight in the range of interest, three of which were new and are here proposed as potential antimicrobial protein candidates by in silico analysis of their amino acid sequences. Mass spectrometric analysis also indicated the presence of partial sequences of antimicrobial enzymes, amidase and dd-carboxypeptidase. Full article

(This article belongs to the Special Issue Drug Delivery and Antimicrobial Agents)

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Open AccessArticle

Polymeric Nanoparticle-Based Photodynamic Therapy for Chronic Periodontitis in Vivo

by Laura Marise De Freitas, Giovana Maria Fioramonti Calixto, Marlus Chorilli, Juçaíra Stella M. Giusti, Vanderlei Salvador Bagnato, Nikolaos S. Soukos, Mansoor M. Amiji and Carla Raquel Fontana

Int. J. Mol. Sci. 2016, 17(5), 769; https://doi.org/10.3390/ijms17050769 - 20 May 2016

Cited by 86 | Viewed by 10797

Abstract

Antimicrobial photodynamic therapy (aPDT) is increasingly being explored for treatment of periodontitis. Here, we investigated the effect of aPDT on human dental plaque bacteria in suspensions and biofilms in vitro using methylene blue (MB)-loaded poly(lactic-co-glycolic) (PLGA) nanoparticles (MB-NP) and red light [...] Read more.

Antimicrobial photodynamic therapy (aPDT) is increasingly being explored for treatment of periodontitis. Here, we investigated the effect of aPDT on human dental plaque bacteria in suspensions and biofilms in vitro using methylene blue (MB)-loaded poly(lactic-co-glycolic) (PLGA) nanoparticles (MB-NP) and red light at 660 nm. The effect of MB-NP-based aPDT was also evaluated in a clinical pilot study with 10 adult human subjects with chronic periodontitis. Dental plaque samples from human subjects were exposed to aPDT—in planktonic and biofilm phases—with MB or MB-NP (25 µg/mL) at 20 J/cm² in vitro. Patients were treated either with ultrasonic scaling and scaling and root planing (US + SRP) or ultrasonic scaling + SRP + aPDT with MB-NP (25 µg/mL and 20 J/cm²) in a split-mouth design. In biofilms, MB-NP eliminated approximately 25% more bacteria than free MB. The clinical study demonstrated the safety of aPDT. Both groups showed similar improvements of clinical parameters one month following treatments. However, at three months ultrasonic SRP + aPDT showed a greater effect (28.82%) on gingival bleeding index (GBI) compared to ultrasonic SRP. The utilization of PLGA nanoparticles encapsulated with MB may be a promising adjunct in antimicrobial periodontal treatment. Full article

(This article belongs to the Special Issue Drug Delivery and Antimicrobial Agents)

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Antibacterial Activity of Ciprofloxacin-Encapsulated Cockle Shells Calcium Carbonate (Aragonite) Nanoparticles and Its Biocompatability in Macrophage J774A.1

by Tijani Isa, Zuki Abu Bakar Zakaria, Yaya Rukayadi, Mohd Noor Mohd Hezmee, Alhaji Zubair Jaji, Mustapha Umar Imam, Nahidah Ibrahim Hammadi and Saffanah Khuder Mahmood

Int. J. Mol. Sci. 2016, 17(5), 713; https://doi.org/10.3390/ijms17050713 - 19 May 2016

Cited by 44 | Viewed by 9860

Abstract

The use of nanoparticle delivery systems to enhance intracellular penetration of antibiotics and their retention time is becoming popular. The challenge, however, is that the interaction of nanoparticles with biological systems at the cellular level must be established prior to biomedical applications. Ciprofloxacin–cockle [...] Read more.

The use of nanoparticle delivery systems to enhance intracellular penetration of antibiotics and their retention time is becoming popular. The challenge, however, is that the interaction of nanoparticles with biological systems at the cellular level must be established prior to biomedical applications. Ciprofloxacin–cockle shells-derived calcium carbonate (aragonite) nanoparticles (C-CSCCAN) were developed and characterized. Antibacterial activity was determined using a modified disc diffusion protocol on Salmonella Typhimurium (S. Typhimurium). Biocompatibilittes with macrophage were evaluated using the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and 5-Bromo-2′-deoxyuridine (BrdU) assays. Transcriptional regulation of interleukin 1 beta (IL-1β) was determined using reverse transcriptase-polymerase chain reaction (RT-PCR). C-CSCCAN were spherical in shape, with particle sizes ranging from 11.93 to 22.12 nm. Encapsulation efficiency (EE) and loading content (LC) were 99.5% and 5.9%, respectively, with negative ζ potential. X-ray diffraction patterns revealed strong crystallizations and purity in the formulations. The mean diameter of inhibition zone was 18.6 ± 0.5 mm, which was better than ciprofloxacin alone (11.7 ± 0.9 mm). Study of biocompatability established the cytocompatability of the delivery system without upregulation of IL-1β. The results indicated that ciprofloxacin–nanoparticles enhanced the antibacterial efficacy of the antibiotic, and could act as a suitable delivery system against intracellular infections. Full article

(This article belongs to the Special Issue Drug Delivery and Antimicrobial Agents)

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pH-Responsive Hyaluronic Acid-Based Mixed Micelles for the Hepatoma-Targeting Delivery of Doxorubicin

by Jing-Liang Wu, Gui-Xiang Tian, Wen-Jing Yu, Guang-Tao Jia, Tong-Yi Sun and Zhi-Qin Gao

Int. J. Mol. Sci. 2016, 17(4), 364; https://doi.org/10.3390/ijms17040364 - 30 Mar 2016

Cited by 47 | Viewed by 9631

Abstract

The tumor targetability and stimulus responsivity of drug delivery systems are crucial in cancer diagnosis and treatment. In this study, hepatoma-targeting mixed micelles composed of a hyaluronic acid–glycyrrhetinic acid conjugate and a hyaluronic acid-l-histidine conjugate (HA–GA/HA–His) were prepared through ultrasonic dispersion. [...] Read more.

The tumor targetability and stimulus responsivity of drug delivery systems are crucial in cancer diagnosis and treatment. In this study, hepatoma-targeting mixed micelles composed of a hyaluronic acid–glycyrrhetinic acid conjugate and a hyaluronic acid-l-histidine conjugate (HA–GA/HA–His) were prepared through ultrasonic dispersion. The formation and characterization of the mixed micelles were confirmed via ¹H-NMR, particle size, and ζ potential measurements. The in vitro cellular uptake of the micelles was evaluated using human liver carcinoma (HepG2) cells. The antitumor effect of doxorubicin (DOX)-loaded micelles was investigated in vitro and in vivo. Results indicated that the DOX-loaded HA–GA/HA–His micelles showed a pH-dependent controlled release and were remarkably absorbed by HepG2 cells. Compared with free DOX, the DOX-loaded HA–GA/HA–His micelles showed a higher cytotoxicity to HepG2 cells. Moreover, the micelles effectively inhibited tumor growth in H22 cell-bearing mice. These results suggest that the HA–GA/HA–His mixed micelles are a good candidate for drug delivery in the prevention and treatment of hepatocarcinoma. Full article

(This article belongs to the Special Issue Drug Delivery and Antimicrobial Agents)

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Open AccessArticle

Laminin Receptor-Avid Nanotherapeutic EGCg-AuNPs as a Potential Alternative Therapeutic Approach to Prevent Restenosis

by Menka Khoobchandani, Kavita Katti, Adam Maxwell, William P. Fay and Kattesh V. Katti

Int. J. Mol. Sci. 2016, 17(3), 316; https://doi.org/10.3390/ijms17030316 - 1 Mar 2016

Cited by 35 | Viewed by 6484

Abstract

In our efforts to develop new approaches to treat and prevent human vascular diseases, we report herein our results on the proliferation and migration of human smooth muscles cells (SMCs) and endothelial cells (ECs) using epigallocatechin-3-gallate conjugated gold nanoparticles (EGCg-AuNPs) as possible alternatives [...] Read more.

In our efforts to develop new approaches to treat and prevent human vascular diseases, we report herein our results on the proliferation and migration of human smooth muscles cells (SMCs) and endothelial cells (ECs) using epigallocatechin-3-gallate conjugated gold nanoparticles (EGCg-AuNPs) as possible alternatives to drug coated stents. Detailed in vitro stability studies of EGCg-AuNPs in various biological fluids, affinity and selectivity towards SMCs and ECs have been investigated. The EGCg-AuNPs showed selective inhibitory efficacy toward the migration of SMCs. However, the endothelial cells remained unaffected under similar experimental conditions. The cellular internalization studies have indicated that EGCg-AuNPs internalize into the SMCs and ECs within short periods of time through laminin receptor mediated endocytosis mode. Favorable toxicity profiles and selective affinity toward SMCs and ECs suggest that EGCg-AuNPs may provide attractive alternatives to drug coated stents and therefore offer new therapeutic approaches in treating cardiovascular diseases. Full article

(This article belongs to the Special Issue Drug Delivery and Antimicrobial Agents)

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Two Different Approaches for Oral Administration of Voriconazole Loaded Formulations: Electrospun Fibers versus β-Cyclodextrin Complexes

by Panoraia I. Siafaka, Neslihan Üstündağ Okur, Mariza Mone, Spyridoula Giannakopoulou, Sevda Er, Eleni Pavlidou, Evangelos Karavas and Dimitrios N. Bikiaris

Int. J. Mol. Sci. 2016, 17(3), 282; https://doi.org/10.3390/ijms17030282 - 25 Feb 2016

Cited by 53 | Viewed by 6362

Abstract

In this work, a comparison between two different preparation methods for the improvement of dissolution rate of an antifungal agent is presented. Poly(ε-caprolactone) (PCL) electrospun fibers and β-cyclodextrin (β-CD) complexes, which were produced via an electrospinning process and an inclusion complexation method, respectively, [...] Read more.

In this work, a comparison between two different preparation methods for the improvement of dissolution rate of an antifungal agent is presented. Poly(ε-caprolactone) (PCL) electrospun fibers and β-cyclodextrin (β-CD) complexes, which were produced via an electrospinning process and an inclusion complexation method, respectively, were addressed for the treatment of fungal infections. Voriconazole (VRCZ) drug was selected as a model drug. PCL nanofibers were characterized on the basis of morphology while phase solubility studies for β-CDs complexes were performed. Various concentrations (5, 10, 15 and 20 wt %) of VRCZ were loaded to PCL fibers and β-CD inclusions to study the in vitro release profile as well as in vitro antifungal activity. The results clearly indicated that all formulations showed an improved VRCZ solubility and can inhibit fungi proliferation. Full article

(This article belongs to the Special Issue Drug Delivery and Antimicrobial Agents)

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K88 Fimbrial Adhesin Targeting of Microspheres Containing Gentamicin Made with Albumin Glycated with Lactose

by Andre-i Sarabia-Sainz, Hector Manuel Sarabia-Sainz, Gabriela Ramos-Clamont Montfort, Veronica Mata-Haro, Ana María Guzman-Partida, Roberto Guzman, Mariano Garcia-Soto and Luz Vazquez-Moreno

Int. J. Mol. Sci. 2015, 16(9), 22425-22437; https://doi.org/10.3390/ijms160922425 - 16 Sep 2015

Cited by 2 | Viewed by 5735

Abstract

The formulation and characterization of gentamicin-loaded microspheres as a delivery system targeting enterotoxigenic Escherichia coli K88 (E. coli K88) was investigated. Glycated albumin with lactose (BSA-glucose-β (4-1) galactose) was used as the microsphere matrix (MS-Lac) and gentamicin included as the transported antibiotic. [...] Read more.

The formulation and characterization of gentamicin-loaded microspheres as a delivery system targeting enterotoxigenic Escherichia coli K88 (E. coli K88) was investigated. Glycated albumin with lactose (BSA-glucose-β (4-1) galactose) was used as the microsphere matrix (MS-Lac) and gentamicin included as the transported antibiotic. The proposed target strategy was that exposed galactoses of MS-Lac could be specifically recognized by E. coli K88 adhesins, and the delivery of gentamicin would inhibit bacterial growth. Lactosylated microspheres (MS-Lac1, MS-Lac2 and MS-Lac3) were obtained using a water-in-oil emulsion, containing gentamicin, followed by crosslinking with different concentrations of glutaraldehyde. Electron microscopy displayed spherical particles with a mean size of 10–17 µm. In vitro release of gentamicin from MS-Lac was best fitted to a first order model, and the antibacterial activity of encapsulated and free gentamicin was comparable. MS-Lac treatments were recognized by plant galactose-specific lectins from Ricinus communis and Sophora japonica and by E. coli K88 adhesins. Results indicate MS-Lac1, produced with 4.2 mg/mL of crosslinker, as the best treatment and that lactosylated microsphere are promising platforms to obtain an active, targeted system against E. coli K88 infections. Full article

(This article belongs to the Special Issue Drug Delivery and Antimicrobial Agents)

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The Effect of Cationic Polyamidoamine Dendrimers on Physicochemical Characteristics of Hydrogels with Erythromycin

by Magdalena Wróblewska and Katarzyna Winnicka

Int. J. Mol. Sci. 2015, 16(9), 20277-20289; https://doi.org/10.3390/ijms160920277 - 27 Aug 2015

Cited by 29 | Viewed by 5540

Abstract

Polyamidoamine dendrimers (PAMAM) represent a new class of hyperbranched, monodisperse, three-dimensional polymers with unique properties, which make them very promising carriers of antimicrobial agents. The present study aimed to evaluate the influence of PAMAM-NH₂ dendrimers generation two (G2) or three (G3) on [...] Read more.

Polyamidoamine dendrimers (PAMAM) represent a new class of hyperbranched, monodisperse, three-dimensional polymers with unique properties, which make them very promising carriers of antimicrobial agents. The present study aimed to evaluate the influence of PAMAM-NH₂ dendrimers generation two (G2) or three (G3) on physicochemical characteristics and structure of hydrogels with a model antibacterial lipophilic drug—erythromycin—commonly used in topical applications. From the obtained rheograms, it can be concluded that tested hydrogels were non-Newtonian thixotropic systems with shear-thinning behaviour. The dissolution tests revealed that erythromycin was definitely faster released from formulations containing PAMAM-NH₂ in concentration and generation dependent manner. However, the addition of PAMAM-NH₂ to hydrogels evoked only slight improvement of their antibacterial activity. It was also shown that the structure of hydrogels changed in the presence of PAMAM-NH₂ becoming less compact, diversified and more porous. Designed hydrogels with PAMAM-NH₂ G2 or G3 were stable stored up to three months at 40 ± 2 °C and 75% ± 5% RH. Full article

(This article belongs to the Special Issue Drug Delivery and Antimicrobial Agents)

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Review

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Open AccessReview

Inhalable Antimicrobials for Treatment of Bacterial Biofilm-Associated Sinusitis in Cystic Fibrosis Patients: Challenges and Drug Delivery Approaches

by Sylvia Natalie Kłodzińska, Petra Alexandra Priemel, Thomas Rades and Hanne Mørck Nielsen

Int. J. Mol. Sci. 2016, 17(10), 1688; https://doi.org/10.3390/ijms17101688 - 9 Oct 2016

Cited by 20 | Viewed by 8023

Abstract

Bacterial biofilm-associated chronic sinusitis in cystic fibrosis (CF) patients caused by Pseudomonas aeruginosa infections and the lack of available treatments for such infections constitute a critical aspect of CF disease management. Currently, inhalation therapies to combat P. aeruginosa infections in CF patients are [...] Read more.

Bacterial biofilm-associated chronic sinusitis in cystic fibrosis (CF) patients caused by Pseudomonas aeruginosa infections and the lack of available treatments for such infections constitute a critical aspect of CF disease management. Currently, inhalation therapies to combat P. aeruginosa infections in CF patients are focused mainly on the delivery of antimicrobials to the lower respiratory tract, disregarding the sinuses. However, the sinuses constitute a reservoir for P. aeruginosa growth, leading to re-infection of the lungs, even after clearing an initial lung infection. Eradication of P. aeruginosa from the respiratory tract after a first infection has been shown to delay chronic pulmonary infection with the bacteria for up to two years. The challenges with providing a suitable treatment for bacterial sinusitis include: (i) identifying a suitable antimicrobial compound; (ii) selecting a suitable device to deliver the drug to the sinuses and nasal cavities; and (iii) applying a formulation design, which will mediate delivery of a high dose of the antimicrobial directly to the site of infection. This review highlights currently available inhalable antimicrobial formulations for treatment and management of biofilm infections caused by P. aeruginosa and discusses critical issues related to novel antimicrobial drug formulation design approaches. Full article

(This article belongs to the Special Issue Drug Delivery and Antimicrobial Agents)

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Marine Antimicrobial Peptides: Nature Provides Templates for the Design of Novel Compounds against Pathogenic Bacteria

by Annarita Falanga, Lucia Lombardi, Gianluigi Franci, Mariateresa Vitiello, Maria Rosaria Iovene, Giancarlo Morelli, Massimiliano Galdiero and Stefania Galdiero

Int. J. Mol. Sci. 2016, 17(5), 785; https://doi.org/10.3390/ijms17050785 - 21 May 2016

Cited by 111 | Viewed by 11160

Abstract

The discovery of antibiotics for the treatment of bacterial infections brought the idea that bacteria would no longer endanger human health. However, bacterial diseases still represent a worldwide treat. The ability of microorganisms to develop resistance, together with the indiscriminate use of antibiotics, [...] Read more.

The discovery of antibiotics for the treatment of bacterial infections brought the idea that bacteria would no longer endanger human health. However, bacterial diseases still represent a worldwide treat. The ability of microorganisms to develop resistance, together with the indiscriminate use of antibiotics, is mainly responsible for this situation; thus, resistance has compelled the scientific community to search for novel therapeutics. In this scenario, antimicrobial peptides (AMPs) provide a promising strategy against a wide array of pathogenic microorganisms, being able to act directly as antimicrobial agents but also being important regulators of the innate immune system. This review is an attempt to explore marine AMPs as a rich source of molecules with antimicrobial activity. In fact, the sea is poorly explored in terms of AMPs, but it represents a resource with plentiful antibacterial agents performing their role in a harsh environment. For the application of AMPs in the medical field limitations correlated to their peptide nature, their inactivation by environmental pH, presence of salts, proteases, or other components have to be solved. Thus, these peptides may act as templates for the design of more potent and less toxic compounds. Full article

(This article belongs to the Special Issue Drug Delivery and Antimicrobial Agents)

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Open AccessReview

Design and Application of Antimicrobial Peptide Conjugates

by Andre Reinhardt and Ines Neundorf

Int. J. Mol. Sci. 2016, 17(5), 701; https://doi.org/10.3390/ijms17050701 - 11 May 2016

Cited by 137 | Viewed by 11151

Abstract

Antimicrobial peptides (AMPs) are an interesting class of antibiotics characterized by their unique antibiotic activity and lower propensity for developing resistance compared to common antibiotics. They belong to the class of membrane-active peptides and usually act selectively against bacteria, fungi and protozoans. AMPs, [...] Read more.

Antimicrobial peptides (AMPs) are an interesting class of antibiotics characterized by their unique antibiotic activity and lower propensity for developing resistance compared to common antibiotics. They belong to the class of membrane-active peptides and usually act selectively against bacteria, fungi and protozoans. AMPs, but also peptide conjugates containing AMPs, have come more and more into the focus of research during the last few years. Within this article, recent work on AMP conjugates is reviewed. Different aspects will be highlighted as a combination of AMPs with antibiotics or organometallic compounds aiming to increase antibacterial activity or target selectivity, conjugation with photosensitizers for improving photodynamic therapy (PDT) or the attachment to particles, to name only a few. Owing to the enormous resonance of antimicrobial conjugates in the literature so far, this research topic seems to be very attractive to different scientific fields, like medicine, biology, biochemistry or chemistry. Full article

(This article belongs to the Special Issue Drug Delivery and Antimicrobial Agents)

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Biomaterials with Antibacterial and Osteoinductive Properties to Repair Infected Bone Defects

by Haiping Lu, Yi Liu, Jing Guo, Huiling Wu, Jingxiao Wang and Gang Wu

Int. J. Mol. Sci. 2016, 17(3), 334; https://doi.org/10.3390/ijms17030334 - 3 Mar 2016

Cited by 150 | Viewed by 13121

Abstract

The repair of infected bone defects is still challenging in the fields of orthopedics, oral implantology and maxillofacial surgery. In these cases, the self-healing capacity of bone tissue can be significantly compromised by the large size of bone defects and the potential/active bacterial [...] Read more.

The repair of infected bone defects is still challenging in the fields of orthopedics, oral implantology and maxillofacial surgery. In these cases, the self-healing capacity of bone tissue can be significantly compromised by the large size of bone defects and the potential/active bacterial activity. Infected bone defects are conventionally treated by a systemic/local administration of antibiotics to control infection and a subsequent implantation of bone grafts, such as autografts and allografts. However, these treatment options are time-consuming and usually yield less optimal efficacy. To approach these problems, novel biomaterials with both antibacterial and osteoinductive properties have been developed. The antibacterial property can be conferred by antibiotics and other novel antibacterial biomaterials, such as silver nanoparticles. Bone morphogenetic proteins are used to functionalize the biomaterials with a potent osteoinductive property. By manipulating the carrying modes and release kinetics, these biomaterials are optimized to maximize their antibacterial and osteoinductive functions with minimized cytotoxicity. The findings, in the past decade, have shown a very promising application potential of the novel biomaterials with the dual functions in treating infected bone defects. In this review, we will summarize the current knowledge of novel biomaterials with both antibacterial and osteoinductive properties. Full article

(This article belongs to the Special Issue Drug Delivery and Antimicrobial Agents)

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