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1.
Turk J Chem ; 47(1): 101-115, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37720862

RESUMO

Collagen type I is the main structural unit in skin tissue and is therefore used preferentially in skin tissue scaffolds. However, collagen-based 3D scaffolds have weak aqueous stability and degradation profiles in their uncross-linked states and chemical cross-linking reagents arise toxicity concerns, which generally restrict the spectrum of their biomedical applicability. Here, the research goal is to photochemically cross-link collagen type I with rose bengal (RB) when subjected to green laser light and to investigate the effect of silk sericin-capped gold nanoparticles (S-AuNP) when incorporated into scaffolds on the cross-linking process and thus on the scaffold properties. All the collagen scaffolds, that is plain collagen (C), collagen/S-AuNP (C-Au), cross-linked collagen (C-RBL), and cross-linked collagen/S-AuNP (C-AuRBL) were characterized for their potential as skin tissue scaffolds. C-AuRBL group had the best thermal stability, resistance to enzymatic degradation, and more uniform pore size distribution. None of the groups had cytotoxicity (cell viability > 70%) regarding the microscopic observations and MTT cell viability assays for L929 fibroblasts. L929 fibroblasts and primary adult human epidermal keratinocytes (HEKa) were also separately seeded on C-AuRBL scaffolds and according to microscopy results, they could support the stimulation of adhesion, morphological changes, and spreading of both cells, thereby encouraging the usage of this fabrication strategy for prospective skin tissue scaffolds.

2.
Int J Pharm ; 614: 121436, 2022 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-34974152

RESUMO

Recently, functional dressings that can protect the wound area from dehydration and bacterial infection and support healing have gained importance in place of passive dressings. This study aimed to develop temporary and regenerative xanthan/gelatin (XGH) and keratin/xanthan/gelatin hydrogels (KXGHs) that have high absorption capacity and applicability as a wound dressing that can provide local delivery of Vitamin C (VC). Firstly, xanthan/gelatin hydrogels were produced by crosslinking with different glycerol concentrations and characterized to determine the hydrogel composition. According to their weight ratios, xanthan, gelatin, and glycerol hydrogels are named. If their weight ratio is 1:1:2 (w/w/w), the group name is selected as X1:GEL1:GLY2. X1:GEL1:GLY2 hydrogel was selected for biocompatibility, mechanical property, water vapor transmission rate (WVTR), and porosity. The addition of keratin to X1:GEL1:GLY2 improved L929 fibroblasts viability and increased protein release. Water vapor transmission of XGHs and KXGHs was between 3059.09 ± 126 and 4523 ± 133 g m-2 d-1; therefore, they can be suitable for granulating, low to moderate exudate wounds. XGH and KXGHs loaded with VC had higher water uptake, making it more convenient for exudate wounds. VC was released for 100 h, and VC containing XGHs and KXGHs increased the collagen synthesis of L929 fibroblasts. All of the hydrogels (XGH, KXGH, and VC-KXGHs) inhibited the bacteria transmission. In conclusion, our results suggest that VC-XGH and VC-KXGH can be candidates for temporary wound dressing materials for skin wounds.


Assuntos
Gelatina , Queratinas , Ácido Ascórbico , Bandagens , Hidrogéis , Polissacarídeos Bacterianos
3.
J Tissue Eng Regen Med ; 14(1): 3-15, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31475790

RESUMO

In this study, clinoptilolite (CLN) was employed as a reinforcement in a polymer-based composite scaffold in bone tissue engineering and evaluated in vivo for the first time. Highly porous, mechanically stable, and osteogenic CLN/PCL-PEG-PCL (CLN/PCEC) scaffolds were fabricated with modified particulate leaching/compression molding technique with varying CLN contents. We hypothesized that CLN reinforcement in a composite scaffold will improve bone regeneration and promote repair. Therefore, the scaffolds were analyzed for compressive strength, biodegradation, biocompatibility, and induction of osteogenic differentiation in vitro. CLN inclusion in PC-10 (10% w/w) and PC-20 (20% w/w) scaffolds revealed 54.7% and 53.4% porosity, higher dry (0.62 and 0.76 MPa), and wet (0.37 and 0.45 MPa) compressive strength, greater cellular adhesion, alkaline phosphatase activity (2.20 and 2.82 mg/gDNA /min), and intracellular calcium concentration (122.44 and 243.24 g Ca/mgDNA ). The scaffolds were evaluated in a unicortical bone defect at anterior aspect of proximal tibia of adult rabbits 4 and 8 weeks postimplantation. Similar to in vitro results, CLN-containing scaffolds led to efficient regeneration of bone in a dose-dependent manner. PC-20 demonstrated highest quality of bone union, cortex development, and bone-scaffold interaction at the defect site. Therefore, higher CLN content in PC-20 permitted robust remodeling whereas pure PCEC (PC-0) scaffolds displayed fibrous tissue formation. Consequently, CLN was proven to be a potent reinforcement in terms of promoting mechanical, physical, and biological properties of polymer-based scaffolds in a more economical, easy-to-handle, and reproducible approach.


Assuntos
Regeneração Óssea/efeitos dos fármacos , Poliésteres/química , Polietilenoglicóis/química , Alicerces Teciduais/química , Zeolitas/química , Fosfatase Alcalina/metabolismo , Animais , Materiais Biocompatíveis/química , Diferenciação Celular , Linhagem Celular , Força Compressiva , Meios de Cultura , Feminino , Humanos , Técnicas In Vitro , Osteoblastos/metabolismo , Osteogênese , Polímeros/química , Porosidade , Coelhos , Estresse Mecânico , Engenharia Tecidual/métodos , Raios Ultravioleta
4.
J Biomed Mater Res A ; 107(12): 2667-2679, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31393664

RESUMO

Herein, an easy one-pot synthesis method for gold nanoparticles (AuNPs), involving only gold salt and sericin extracted from silkworm cocoon in the presence of ultraviolet C (UVC) radiation, was developed. Nanoparticle formation was confirmed by characteristic surface plasmon resonance peaks at 520-540 nm wavelengths, and the influence of silk sericin on enhancing the colloidal stability of AuNPs was confirmed. Transmission electron microscopy examination showed the average size (<10 nm) and size distribution decreased significantly with higher sericin concentration. No antibacterial activity was observed on Gram-positive Bacillus subtilis or Gram-negative Escherichia coli for sole AuNPs (0.065-0.26 mg/ml), but the conjugation of AuNPs with streptomycin antibiotic decreased significantly the required minimum inhibitory concentration doses, as also confirmed with agar plating, Scanning Electron Microscopy and Atomic Force Microscopy analyses. Furthermore, sericin-capped AuNPs showed high cell viabilities (>100%) and no sign of any detectable apoptosis or necrosis in 1-day incubation. Also, high real-time cell proliferation results of AuNPs competitive with positive control groups implied excellent in vitro biocompatibility. These results evidenced that sericin enhanced the colloidal stability of AuNPs and the biological activities of sericin-capped AuNPs reported here could render them suitable nanoscale vehicles for biomedical applications.


Assuntos
Antibacterianos/química , Materiais Biocompatíveis/química , Ouro/química , Nanopartículas Metálicas/química , Sericinas/química , Animais , Antibacterianos/síntese química , Antibacterianos/farmacologia , Bacillus subtilis/efeitos dos fármacos , Materiais Biocompatíveis/farmacologia , Bombyx/química , Escherichia coli/efeitos dos fármacos , Infecções por Escherichia coli/prevenção & controle , Ouro/farmacologia , Humanos , Sericinas/síntese química , Sericinas/farmacologia
5.
ACS Appl Mater Interfaces ; 10(39): 33545-33555, 2018 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-30192508

RESUMO

Antibiotic resistance in bacterial cells has motivated the scientific community to design new and efficient (bio)materials with targeted bacteriostatic and/or bactericide properties. In this work, a series of polyelectrolyte multilayer films differing in terms of polycation-polyanion combinations are constructed according to the layer-by-layer deposition method. Their capacities to host T4 and φx174 phage particles and maintain their infectivity and bacteriolytic activity are thoroughly examined. It is found that the macroscopic physicochemical properties of the films, which includes film thickness, swelling ratio, or mechanical stiffness (as derived by atomic force microscopy and spectroscopy measurements), do not predominantly control the selectivity of the films for hosting infective phages. Instead, it is evidenced that the intimate electrostatic interactions locally operational between the loaded phages and the polycationic and polyanionic PEM components may lead to phage activity reduction and preservation/enhancement, respectively. It is argued that the underlying mechanism involves the screening of the phage capsid receptors (operational in cell recognition/infection processes) because of the formation of either polymer-phage hetero-assemblies or polymer coating surrounding the bioactive phage surface.


Assuntos
Bacteriófagos/patogenicidade , Materiais Biocompatíveis/química , Bioensaio/métodos , Polímeros/química , Difusão Dinâmica da Luz , Microscopia de Força Atômica , Polieletrólitos
6.
J Biomater Appl ; 31(8): 1148-1168, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27881642

RESUMO

The aim of this study was to prepare and characterize highly porous clinoptilolite/poly(ε-caprolactone)-poly(ethylene glycol)-poly(ε-caprolactone) composite scaffolds. Scaffolds with different clinoptilolite contents (10% and 20%) were fabricated with reproducible solvent-free powder compression/particulate leaching technique. The scaffolds had interconnective porosity in the range of 55-76%. Clinoptilolite/poly(ε-caprolactone)-poly(ethylene glycol)-poly(ε-caprolactone) scaffolds showed negligible degradation within eight weeks and displayed less water uptake and higher bioactivity than poly(ε-caprolactone)-poly(ethylene glycol)-poly(ε-caprolactone) scaffolds. The presence of clinoptilolite improved the mechanical properties. Highest compressive strength (5.6 MPa) and modulus (114.84 MPa) were reached with scaffold group containing 20% clinoptilolite. In vitro protein adsorption capacity of the scaffolds was also higher for clinoptilolite/poly(ε-caprolactone)-poly(ethylene glycol)-poly(ε-caprolactone) scaffolds. These scaffolds had 0.95 mg protein/g scaffold adsorption capacity and also higher osteoinductivity in terms of enhanced ALP, OSP activities and intracellular calcium deposition. Stoichiometric apatite deposition (Ca/P=1.686) was observed during cellular proliferation analysis with human fetal osteoblasts cells. Thus, it can be suggested that clinoptilolite/poly(ε-caprolactone)-poly(ethylene glycol)-poly(ε-caprolactone) composite scaffolds could be promising carriers for enhancement of bone regeneration in bone tissue engineering applications.


Assuntos
Substitutos Ósseos/síntese química , Nanocompostos/química , Osteoblastos/fisiologia , Poliésteres/química , Polietilenoglicóis/química , Engenharia Tecidual/instrumentação , Alicerces Teciduais , Zeolitas/química , Linhagem Celular , Proliferação de Células/fisiologia , Força Compressiva , Módulo de Elasticidade , Desenho de Equipamento , Análise de Falha de Equipamento , Humanos , Teste de Materiais , Nanocompostos/ultraestrutura , Nanoporos/ultraestrutura , Osteoblastos/citologia , Porosidade , Estresse Mecânico , Engenharia Tecidual/métodos
7.
Mater Sci Eng C Mater Biol Appl ; 48: 391-9, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25579939

RESUMO

Protein instability during microencapsulation has been one of the major drawbacks of protein delivery systems. In this study, the effects of various excipients (poly vinyl alcohol, glucose, starch, heparin) on the stability of encapsulated human immunoglobulin G (IgG) in poly(ε-caprolactone) (PCL) microspheres and on microsphere characteristics were investigated before and after γ-sterilization. Microspheres formulated without any excipients and with glucose had a mean particle size around 3-4µm whereas the mean particle sizes of other microspheres were around 5-6µm. Use of PVA significantly increased the IgG-loading and encapsulation efficiency of microspheres. After γ-irradiation, IgG stability was mostly maintained in the microspheres with excipients compared to microspheres without any excipients. According to the µBCA results, microspheres without any excipient showed a high initial burst release as well as a fast release profile among all groups. Presence of PVA decreased the loss in the activity of IgG released before (completely retained after 6h and 15.69% loss after 7days) and after γ-irradiation (26.04% loss and 52.39% loss after 6h and 7days, respectively). The stabilization effect of PVA on the retention of the activity of released IgG was found more efficient compared to other groups formulated with carbohydrates.


Assuntos
Excipientes/química , Raios gama , Imunoglobulina G/química , Microesferas , Poliésteres/química , Esterilização , Preparações de Ação Retardada , Humanos , Estabilidade Proteica/efeitos da radiação
8.
J Biomater Appl ; 29(4): 524-42, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24854983

RESUMO

Anti-tumor necrosis factor α (TNFα) drugs such as etanercept (ETN) have been mostly used in systemic treatment of rheumatoid arthritis. To eliminate the side effects in long-term treatments and to achieve a local sustained anti-inflammatory effect, a controlled drug delivery system is needed for anti-TNFα drugs. This study aims to develop novel injectable microcarriers of ETN that can provide long-term controlled release of this protein drug upon intra-articular application. In this study, poly(ε-caprolactone) (PCL) and its copolymer with poly(ethylene glycol), methoxypoly(ethylene glycol)-poly(ε-caprolactone)-methoxypoly(ethylene glycol) microspheres (MPEG-PCL-MPEG) were compared for their prospective success in rheumatoid arthritis treatment. Microspheres with smooth surface of a mean particle diameter of approximately 5 µm were prepared with both polymers. MPEG-PCL-MPEG microspheres had higher encapsulation efficiency than PCL microspheres. The activity of encapsulated ETN within MPEG-PCL-MPEG microspheres also retained while 90% of the activity of ETN within PCL microspheres could retain during 90-day release. MPEG-PCL-MPEG microspheres showed faster ETN release compared to PCL microspheres in various release media. Cumulative amounts of ETN released from both types of microspheres were significantly lower in cell culture medium and in synovial fluids than in phosphate buffered saline. This was mainly due to protein adsorption onto microspheres. Hydrophilic MPEG segment enhanced ETN release while preventing protein adsorption on microspheres compared to PCL. Sustained ETN release from microspheres resulted with a significant decrease in pro-inflammatory cytokines (TNFα, IFNγ, IL-6, IL-17) and MMP levels (MMP-3, MMP-13), while conserving viability of fibroblast-like synoviocytes compared to the free drug. Results suggest that MPEG-PCL-MPEG is a potential copolymer of PCL that can be used in development of biomedical materials for effective local treatment purposes in chronic inflammatory arthritis owing to enhanced hydrophilicity. Yet, PCL microspheres are also promising systems having good compatibility to synoviocytes and would be especially the choice for treatment approach requiring longer term and slower release.


Assuntos
Artrite Reumatoide/tratamento farmacológico , Materiais Biocompatíveis/química , Sistemas de Liberação de Medicamentos , Imunoglobulina G/administração & dosagem , Receptores do Fator de Necrose Tumoral/administração & dosagem , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Artrite Reumatoide/metabolismo , Artrite Reumatoide/patologia , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Citocinas/metabolismo , Preparações de Ação Retardada , Etanercepte , Humanos , Técnicas In Vitro , Mediadores da Inflamação/metabolismo , Injeções Intra-Articulares , Teste de Materiais , Metaloproteinases da Matriz/metabolismo , Microesferas , Tamanho da Partícula , Poliésteres/química , Polietilenoglicóis/química , Membrana Sinovial/efeitos dos fármacos , Membrana Sinovial/metabolismo , Membrana Sinovial/patologia
9.
Colloids Surf B Biointerfaces ; 117: 487-96, 2014 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-24530344

RESUMO

Polyester-polyether type block copolymers have attracted attention in the area of drug delivery systems with their capability in providing a broad range of amphiphilic characteristics. The aim of the present work was to prepare and characterize immunoglobulin G (IgG) loaded methoxy poly(ethylene glycol)-poly(ɛ-caprolactone)-methoxy poly(ethylene glycol) (MPEG-PCL-MPEG) microspheres as potential carrier for therapeutic monoclonal antibodies used in clinics. MPEG-PCL-MPEG triblock copolymer was synthesized by ring-opening polymerization of ɛ-caprolactone initiated by MPEG and then characterized. Microspheres were prepared by double emulsion-solvent evaporation method and their properties were compared with those of PCL microspheres. Microspheres had spherical shape with a mean particle size around 6 µm. MPEG-PCL-MPEG microspheres had higher encapsulation efficiency than PCL microspheres. After 90 days of release, 30±2% and 57±3% of the bioactivity of IgG released from non-irradiated PCL and MPEG-PCL-MPEG microspheres were protected, respectively. Presence of MPEG in microspheres provided more controlled IgG release rate and protected IgG from denaturation during γ-irradiation (20±3% and 49±2% for PCL and MPEG-PCL-MPEG microspheres, respectively). In vitro cytotoxicity tests revealed that both MPEG-PCL-MPEG and PCL microspheres had no toxic effect on cells. This study showed that MPEG-PCL-MPEG microspheres are promising delivery systems for therapeutic monoclonal antibodies.


Assuntos
Imunoglobulina G/metabolismo , Microesferas , Poliésteres/química , Polietilenoglicóis/química , Células 3T3 , Animais , Raios gama , Humanos , Cinética , Camundongos , Microscopia Eletrônica de Varredura , Peso Molecular , Tamanho da Partícula , Poliésteres/síntese química , Polietilenoglicóis/síntese química , Espectroscopia de Prótons por Ressonância Magnética , Espectroscopia de Infravermelho com Transformada de Fourier
10.
Biotechnol Appl Biochem ; 60(6): 603-16, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23586705

RESUMO

This study aimed to investigate the release of cefuroxime axetil (CF) and calcium from poly(ε-caprolactone) (PCL)-calcium sulfate (CaS) implants (PCL:CaS 2:1-10% CF; PCL:CaS 2:1-20% CF; PCL:CaS 1:1-10% CF) for treating infectious bone diseases. Bioactivity, crystallinity and strength, and release profiles under standard and pressurized release conditions were studied. PCL:CaS 2:1-20% CF had slower release than 10% loading. These groups had no significant change in CF and Ca release in response to pressure. The PCL:CaS 1:1 group had the slowest release despite having higher CaS, probably due to more compaction of discs. In contrast, pressure caused significant differentiation of CF and Ca(2+) release. The presence of CaS enhanced mechanical properties and bioactivity of discs. SEM and XPS results showed calcium-phosphate containing accumulations on surfaces upon SBF incubation. CF-loaded implants were applied in a rabbit osteomyelitis model. In vivo CF release was enhanced with increased CaS proportions, suggesting that in vivo release conditions are closer to pressurized in vitro conditions. In the control group, there was still some inflammation in the bone and no complete coverage with bone was achieved in the defect site. Discs provided a suitable surface for regeneration of bone. However, bone formation in the PCL:CaS 1:1 disc implanted group was more complete and regular than in the 2:1 group.


Assuntos
Sulfato de Cálcio/química , Cefuroxima/análogos & derivados , Portadores de Fármacos/química , Osteomielite/tratamento farmacológico , Poliésteres/química , Células 3T3 , Animais , Cefuroxima/química , Cefuroxima/uso terapêutico , Linhagem Celular Tumoral , Portadores de Fármacos/toxicidade , Humanos , Camundongos , Osteomielite/patologia , Coelhos , Temperatura
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