Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.448
Filtrar
1.
Acta Cir Bras ; 34(11): e201901101, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31939594

RESUMO

PURPOSE: To determine the efficacy of norbixin-based poly(hydroxybutyrate) (PHB) membranes for Achilles tendon repair. METHODS: Thirty rats were submitted to total tenotomy surgery of the right Achilles tendon and divided into two groups (control and membrane; n = 15 each), which were further subdivided into three subgroups (days 7, 14, and 21; n = 5 each). Samples were analyzed histologically. RESULTS: Histological analysis showed a significant reduction in inflammatory infiltrates on days 7, 14 (p < 0.0001 for both), and 21 (p = 0.0004) in the membrane group compared to that in the control group. There was also a significant decrease in the number of fibroblasts in the control group on days 7, 14 (p < 0.0001), and 21 (p = 0.0032). Further, an increase in type I collagen deposition was observed in the membrane group compared to that in the control group on days 7 (p = 0.0133) and 14 (p = 0.0107). CONCLUSION: Treatment with norbixin-based PHB membranes reduces the inflammatory response, increases fibroblast proliferation, and improves collagen production in the tendon repair region, especially between days 7 and 14.


Assuntos
Tendão do Calcâneo/efeitos dos fármacos , Tendão do Calcâneo/cirurgia , Carotenoides/farmacologia , Hidroxibutiratos/farmacologia , Poliésteres/farmacologia , Tenotomia/métodos , Tendão do Calcâneo/patologia , Animais , Colágeno Tipo I/análise , Colágeno Tipo I/efeitos dos fármacos , Colágeno Tipo III/análise , Colágeno Tipo III/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Humanos , Masculino , Ratos Wistar , Valores de Referência , Regeneração/efeitos dos fármacos , Reprodutibilidade dos Testes , Fatores de Tempo , Resultado do Tratamento
2.
Mater Sci Eng C Mater Biol Appl ; 108: 110455, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31924042

RESUMO

An amphiphilic biodegradable branched copolymer, mPEG-b-PLGA-g-OCol, was synthesized by grafting copolymer (methoxy polyethylene glycol)-b-Poly (l,d-lactic-co-glycolic acid) (mPEG-b-PLGA) on oligomeric collagen (OCol), to form a branched structure with mPEG-b-PLGA as side chain and OCol as backbone. mPEG-b-PLGA and mPEG-b-PLGA-g-OCol were both amphipathic and can self-assemble into micelles in aqueous solution. The mPEG-b-PLGA-g-OCol micelles showed pH-sensitive behaviors and the particle size below 100 nm in slightly acidic environment such as tumor tissue milieu interieur to perform passive targeting. Observed by SEM, when the solution pH increased from 5 to 9, the morphology of mPEG-b-PLGA-g-OCol micelles changed from small spheres to larger ones to rings. For biodegradable mPEG-b-PLGA-g-OCol, the micelles will gradually degrade in body. Further, doxorubicin (DOX) was effectively loaded in the micelles with drug loading and encapsulation efficiency of 3.48% and 25.8%, respectively. To evaluate antineoplastic effect of DOX-laden micelles in vitro, MTT test, flow cytometry and CLSM were performed and found that DOX-laden micelles exhibited higher cellular proliferation inhibition against HeLa cells. These features indicated that the mPEG-b-PLGA-g-OCol micelles were potential drug carrier for cancer therapy.


Assuntos
Plásticos Biodegradáveis , Portadores de Fármacos , Micelas , Plásticos Biodegradáveis/síntese química , Plásticos Biodegradáveis/química , Plásticos Biodegradáveis/farmacocinética , Plásticos Biodegradáveis/farmacologia , Preparações de Ação Retardada/síntese química , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacocinética , Preparações de Ação Retardada/farmacologia , Doxorrubicina/química , Doxorrubicina/farmacocinética , Doxorrubicina/farmacologia , Portadores de Fármacos/síntese química , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Portadores de Fármacos/farmacologia , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Poliésteres/síntese química , Poliésteres/química , Poliésteres/farmacocinética , Poliésteres/farmacologia , Polietilenoglicóis/síntese química , Polietilenoglicóis/química , Polietilenoglicóis/farmacocinética , Polietilenoglicóis/farmacologia
3.
Carbohydr Polym ; 230: 115640, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31887895

RESUMO

Bone transplantations are still facing many serious challenges, hydrogel as a new kind of artificial bone substitutes has developed into a promising bone scaffold material. However, it is still a challenge to combine bioactive agents and hydrogel matrix to promote osteoinductivity. Herein, we developed a novel bioactive hydrogel based on arginine-based unsaturated poly (ester amide) (Arg-UPEA) and methacrylated hyaluronic acid (HA-MA) via photo-crosslinking. As the results indicated, we found that the introduction of Arg-UPEA into HA-MA hydrogels could finely modulate their compressive modulus, swelling level and porous structure. Besides, among groups of different feed ratio, groups of 10 % and 15 % of Arg-UPEA content effectively enhanced osteogenic differentiation in osteoblasts when compared with HA-MA hydrogel. Furthermore, better bone regeneration and expression of osteogenesis-related factors in vivo also verified the Arg-UPEA/HA-MA hybrid hydrogels as a promising scaffold material for bone tissue engineering.


Assuntos
Substitutos Ósseos/química , Hidrogéis/química , Engenharia Tecidual , Tecidos Suporte/química , Células 3T3 , Amidas/química , Amidas/farmacologia , Animais , Arginina/química , Arginina/farmacologia , Regeneração Óssea , Substitutos Ósseos/uso terapêutico , Osso e Ossos , Ácido Hialurônico/química , Ácido Hialurônico/farmacologia , Hidrogéis/uso terapêutico , Interações Hidrofóbicas e Hidrofílicas , Metacrilatos/química , Metacrilatos/farmacologia , Camundongos , Células NIH 3T3 , Osteogênese/fisiologia , Poliésteres/química , Poliésteres/farmacologia , Porosidade , Ratos Sprague-Dawley
4.
Cell Prolif ; 53(1): e12730, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31746040

RESUMO

OBJECTIVES: In peripheral neuropathy, the underlying mechanisms of nerve and muscle degeneration include chronic inflammation and oxidative stress in fibrotic tissues. (-)-Epigallocatechin gallate (EGCG) is a major, active component in green tea and may scavenge free radical oxygen and attenuate inflammation. Conservative treatments such as steroid injection only deal with early, asymptomatic, peripheral neuropathy. In contrast, neurolysis and nerve conduit implantation work effectively for treating advanced stages. MATERIALS AND METHODS: An EGCG-loaded polycaprolactone (PCL) porous scaffold was fabricated using an integrated moulding method. We evaluated proliferative, oxidative and inflammatory activity of rat Schwann cells (RSCs) and rat skeletal muscle cells (RSMCs) cultured on different scaffolds in vitro. In a rat radiation injury model, we assessed the morphological, electrophysiological and functional performance of regenerated sciatic nerves and gastrocnemius muscles, as well as oxidative stress and inflammation state. RESULTS: RSCs and RSMCs exhibited higher proliferative, anti-oxidant and anti-inflammatory states in an EGCG/PCL scaffold. In vivo studies showed improved nerve and muscle recovery in the EGCG/PCL group, with increased nerve myelination and muscle fibre proliferation and reduced macrophage infiltration, lipid peroxidation, inflammation and oxidative stress indicators. CONCLUSIONS: The EGCG-modified PCL porous nerve scaffold alleviates cellular oxidative stress and repairs peripheral nerve and muscle structure in rats. It attenuates oxidative stress and inflammation in vivo and may provide further insights into peripheral nerve repair in the future.


Assuntos
Catequina/análogos & derivados , Regeneração Nervosa/efeitos dos fármacos , Neurogênese/efeitos dos fármacos , Estresse Oxidativo , Doenças do Sistema Nervoso Periférico/tratamento farmacológico , Poliésteres , Lesões Experimentais por Radiação/tratamento farmacológico , Células de Schwann/metabolismo , Nervo Isquiático/fisiologia , Tecidos Suporte/química , Animais , Catequina/química , Catequina/farmacologia , Linhagem Celular , Músculo Esquelético/inervação , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Doenças do Sistema Nervoso Periférico/metabolismo , Doenças do Sistema Nervoso Periférico/patologia , Poliésteres/química , Poliésteres/farmacologia , Porosidade , Lesões Experimentais por Radiação/metabolismo , Lesões Experimentais por Radiação/patologia , Ratos , Células de Schwann/patologia , Nervo Isquiático/lesões , Nervo Isquiático/patologia
5.
Carbohydr Polym ; 229: 115422, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31826517

RESUMO

Starch is an attractive biomacromolecule for functional materials due to its renewability, biodegradability, amenability for modification, and biocompatibility in mammalian cell lines. In this research, starch was proposed as a modular platform to produce antimicrobial polymer surfaces. Conjugation of biocidal molecules via chemical grafting onto starch (starch-g-biocide) and its antimicrobial properties in poly (lactic acid) (PLA) polymers were investigated. Polyhexamethylene guanidine hydrochloride (PHGH) was synthesized and used as an antimicrobial agent. The grafting was confirmed by FTIR, proton NMR, and elemental analysis. The modified starch was then incorporated into the PLA films at various concentrations, and the antimicrobial efficacy of these films were evaluated against a Gram-positive bacterium, Bacillus subtilis and a Gram-negative bacterium, Escherichia coli. The results showed that the polymer surfaces have high antimicrobial potency when bacteria contact them. This material therefore has great potential for self-decontaminating surfaces, such as medical devices and food packaging applications.


Assuntos
Antibacterianos , Guanidinas , Poliésteres , Amido , Antibacterianos/química , Antibacterianos/farmacologia , Bacillus subtilis/efeitos dos fármacos , Bacillus subtilis/crescimento & desenvolvimento , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Guanidinas/química , Guanidinas/farmacologia , Poliésteres/química , Poliésteres/farmacologia , Amido/química , Amido/farmacologia
6.
Mater Sci Eng C Mater Biol Appl ; 107: 110301, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31761156

RESUMO

Bone defects are a common clinical situation. However, bone regeneration remains a challenge and faces the limitation of poor engraftment due to deficient vascularisation. Poly-3-hydroxybutyrate-co-3-hydroxyvalerate (PHB-HV) and human adipose stem cells (hASC) are promising for vascularisation and bone regeneration. Therefore, we sought to investigate the bone regenerative capacity of hASCs cultured in allogeneic human serum (aHS) and PHB-HV scaffolds in a nude mouse model of the critical-sized calvarial defect. We evaluated bone healing for three treatment groups: empty (control), PHB-HV and PHB-HV + hASCs. The pre-implant analysis showed that hASCs colonised the PHB-HV scaffolds maintaining cell viability before implantation. Histological analysis revealed that PHB-HV scaffolds were tolerated in vivo; they integrated with adjacent tissue eliciting a response like a foreign body reaction, and tiny primary bone was observed only in the PHB-HV group. Also, the µ-CT analysis revealed only approximately 10% of new bone in the bone defect area in both the PHB-HV and PHB-HV + hASCs groups. The expression of BGLAP and its protein (osteocalcin) by PHB-HV + hASCs group and native bone was similar while the other bone markers RUNX2, ALPL and COL1A1 were upregulated, but this expression remained significantly lower compared to the native bone. Nevertheless, the PHB-HV group showed neovascularisation at 12 weeks post-implantation while PHB-HV + hASCs group also exhibited higher VEGFA expression as well as a higher number of vessels at 4 weeks post-implantation, and, consequently, earlier neovascularisation. This neovascularisation must be due to scaffold architecture, improved by hASCs, that survived for the long term in vivo in the PHB-HV + hASCs group. These results demonstrated that hASCs cultured in aHS combined with PHB-HV scaffolds were ineffective to promote bone regeneration, although the construct of hASCs + PHB-HV in xeno-free conditions improved scaffold vascularisation representing a strategy potentially promising for other tissue engineering applications.


Assuntos
Tecido Adiposo/citologia , Neovascularização Fisiológica/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Poliésteres , Engenharia Tecidual/métodos , Animais , Substitutos Ósseos/química , Substitutos Ósseos/farmacologia , Osso e Ossos/irrigação sanguínea , Osso e Ossos/citologia , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/patologia , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Humanos , Masculino , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Osteocalcina/metabolismo , Poliésteres/química , Poliésteres/farmacologia , Tecidos Suporte
7.
Mater Sci Eng C Mater Biol Appl ; 107: 110296, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31761169

RESUMO

Nanofibrous scaffolds composed of polycaprolactone (PCL) and gelatin (Ge) were obtained through a hydrolytic assisted electrospinning process. The PCL-to-Ge proportion (100/0 to 20/80), as well as the dissolution time (24, 48, 72, 96, 120 h) into a 1:1 formic/acetic acid solvent before electrospinning were modified to obtain the different samples. A strong influence of these factors on the physicochemical properties of the scaffolds was observed. Higher Ge percentage reduced crystallinity, allowed a uniform morphology and increased water contact angle. The increase in the dissolution time considerably reduced the molar mass and, subsequently, fibre diameter and crystallinity were affected. During in vitro biocompatibility tests, higher cell adhesion and proliferation were found for the 60/40, 50/50 and 40/60 PCL/Ge compositions that was corroborated by MTT assay, fluorescence and microscopy. A weakened structure, more labile to the in vitro degradation in physiologic conditions was found for these compositions with higher dissolution times (72 and 96 h). Particularly, the 40/60 PCL/Ge scaffolds revealed an interesting progressive degradation behaviour as a function of the dissolution time. Moreover, these scaffolds were non-inflammatory, as revealed by the pyrogen test and after the 15-day subcutaneous in vivo implantation in mice. Finally, a reduction of the scar tissue area after infarction was found for the 40/60 PCL/Ge scaffolds electrospun after 72 h implanted in rat hearts. These results are especially interesting and represent a feasible way to avoid undesired inflammatory reactions during the scaffold assimilation.


Assuntos
Gelatina , Poliésteres , Tecidos Suporte/química , Animais , Adesão Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Modelos Animais de Doenças , Gelatina/química , Gelatina/farmacologia , Humanos , Leucócitos Mononucleares/efeitos dos fármacos , Teste de Materiais , Camundongos , Camundongos Endogâmicos C57BL , Infarto do Miocárdio/patologia , Miocárdio/patologia , Nanofibras/química , Poliésteres/química , Poliésteres/farmacologia , Ratos , Ratos Wistar , Engenharia Tecidual/métodos
8.
J Colloid Interface Sci ; 560: 795-801, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31711662

RESUMO

Super-amphiphilic (highly oleophilic and hydrophilic) materials have attracted tremendous interest for fundamental research and potential applications, owing to their unique affinity for both oil and water. In this work, a novel super-amphiphilic porous polycaprolactone (PCL) was fabricated via an efficient and eco-friendly method, in which stearic acid (SA) was used as both a porogen and a dopant precursor. The porous PCL had an interconnected hierarchical pore structure and was capable of absorbing oil and water rapidly. The complementary cooperation of the oleophilic and hydrophilic domains on the pore surface induced the amphiphilicity, while the capillary forces caused a wicking action. The synergy of the two effects gave rise to the super-wetting property. The special amphiphilic feature of the porous PCL had a positive effect on its biocompatibility and the material can be considered as a promising candidate for tissue engineering applications.


Assuntos
Materiais Biocompatíveis/síntese química , Proliferação de Células/efeitos dos fármacos , Células Dendríticas/citologia , Teste de Materiais , Poliésteres/síntese química , Ácidos Esteáricos/química , Materiais Biocompatíveis/farmacologia , Adesão Celular , Células Cultivadas , Células Dendríticas/efeitos dos fármacos , Humanos , Interações Hidrofóbicas e Hidrofílicas , Poliésteres/farmacologia , Porosidade , Molhabilidade
9.
Colloids Surf B Biointerfaces ; 185: 110617, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31740326

RESUMO

New biocompatible and bioabsorbable materials are currently being developed for bone regeneration. These serve as scaffolding for controlled drug release and prevent bacterial infections. Films of polylactic acid (PLA) polymers that are Mg-reinforced have demonstrated they have suitable properties and bioactive behavior for promoting the osseointegration process. However little attention has been paid to studying whether the degradation process can alter the adhesive physical properties of the biodegradable film and whether this can modify the biofilm formation capacity of pathogens. Moreover, considering that the concentration of Mg and other corrosion products may not be constant during the degradation process, the question that arises is whether these changes can have negative consequences in terms of the bacterial colonization of surfaces. Bacteria are able to react differently to the same compound, depending on its concentration in the medium and can even become stronger when threatened. In this context, physical surface parameters such as hydrophobicity, surface tension and zeta potential of PLA films reinforced with 10% Mg have been determined before and after degradation, as well as the biofilm formation capacity of Staphylococcus epidermidis. The addition of Mg to the films makes them less hydrophobic and the degradation also reduces the hydrophobicity and increases the negative charge of the surface, especially over long periods of time. Early biofilm formation at 8 h is consistent with the physical properties of the films, where we can observe a reduction in the bacterial biofilm formation. However, after 24 h of incubation, the biofilm formation increases significantly on the PLA/Mg films with respect to PLA control. The explosive release of Mg ions and other corrosion products within the first hours were not enough to prevent a greater biofilm formation after this initial time. Consequently, the Mg addition to the polymer matrix had a bacteriostatic effect but not a bactericidal one. Future works should aim to optimize the design and biofunctionality of these promising bioabsorbable composites for a degradation period suitable for the intended application.


Assuntos
Biofilmes/efeitos dos fármacos , Magnésio/farmacologia , Viabilidade Microbiana/efeitos dos fármacos , Poliésteres/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/ultraestrutura , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Imagem Óptica , Eletricidade Estática , Propriedades de Superfície , Água/química
10.
Med Sci Monit ; 25: 9737-9751, 2019 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-31856143

RESUMO

BACKGROUND This study aimed to prepare doxorubicin- and tetrahydrocurcumin-loaded and transferrin-modified PEG-PLGA nanoparticles (Tf-NPs-DOX-THC) for enhanced and synergistic chemoradiotherapy. MATERIAL AND METHODS Tf-NPs-DOX-THC were prepared via the double-emulsion method. The morphologies and particle sizes of the prepared nanoparticles were examined by TEM and DLS, respectively. The in vitro MTT, apoptosis, and clone formation assays were performed to detect the proliferation and radiosensitivity of cells with various treatments. Cellular uptake assay was also conducted. The tissue distribution of Tf-NPs was investigated by ex vivo DOX fluorescence imaging. The in vivo tumor growth inhibition efficiency of various treatments was evaluated in orthotopic C6 mouse models and C6 subcutaneously grafted mouse models. RESULTS Tf-NPs-DOX-THC exhibited high drug-loading efficiency (6.56±0.32%) and desirable particle size (under 250 nm). MTT, apoptosis, and clone formation assays revealed the enhanced anti-cancer activity and favorable radiosensitizing effect of Tf-NPs-DOX-THC. Strong fluorescence was observed in the brains of mice treated with Tf-NPs-DOX. The in vitro release of drug from nanoparticles was in a pH-sensitive manner. Tf-NPs-DOX-THC in combination with radiation also achieved favorable anti-tumor efficacy in vivo. CONCLUSIONS All results suggest that a combination of Tf-NPs-DOX-THC and radiation is a promising strategy for synergistic and sensitizing chemoradiotherapy of glioma.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Glioma/tratamento farmacológico , Poliésteres/química , Polietilenoglicóis/química , Animais , Linhagem Celular Tumoral , Quimiorradioterapia/métodos , Curcumina/análogos & derivados , Curcumina/farmacologia , Doxorrubicina/farmacologia , Portadores de Fármacos/farmacologia , Emulsões , Glioma/patologia , Humanos , Lactatos/química , Camundongos , Camundongos Nus , Nanopartículas/administração & dosagem , Tamanho da Partícula , Poliésteres/farmacologia , Polietilenoglicóis/farmacologia , Ratos , Distribuição Tecidual , Transferrina/química , Transferrina/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
11.
Georgian Med News ; (294): 145-150, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31687968

RESUMO

The main aim is to find out the mechanisms of reparative regeneration of bone tissue in artificially created transverse mandibular defects in rats when applying osteoplastic materials based on hydroxyapatite and polylactide with different component percentage. Experimental studies were carried out on 114 mature laboratory white male 180-220 g rats that were divided into groups: control group - animals whose bone defect was filled only with a blood clot; 1st experimental group - the entire defect volume was densely filled with a block with the ratio of component parts, hydroxyapatite 80% + polylactide 20%; 2nd experimental group was similar, but with the ratio of 50% + 50%. Morphological and morphometric research methods were carried out after the removed jaws had been decalcized in a 10% nitric acid solution. An x-ray study was performed using an Intra digital radiograph (Planmeca, Finland). Statistical analysis of the results was carried out according to the standard method of descriptive statistics using the software package "StatSoftStatistica 10". The use of osteoplastic material with a longer period of its biodegradation contributes to filling the defect with bone tissue, but slows down the processes of the final formation of a mature secondary bone scar, yet allows even with hypercorrection to restore the anatomical form of the lost area. Therefore, the use of this material is recommended for a defect in the alveolar ridge, mainly in extraction sockets, when one needs to avoid atrophy and to create conditions for prosthetic treatment. Osteoimplant with a faster biodegradation period allows structuring collagen fibers in the regenerate in the early stages of healing, which optimizes the formation of an organic bone matrix and promotes its faster mineralization. Therefore, such bone substitutes can be better used for insignificant defects or when the restoration of the anatomical form is not essential, mainly for defects of the body and mandibular branches.


Assuntos
Perda do Osso Alveolar/tratamento farmacológico , Materiais Biocompatíveis/uso terapêutico , Regeneração Óssea/efeitos dos fármacos , Substitutos Ósseos/farmacologia , Mandíbula/patologia , Poliésteres/farmacologia , Perda do Osso Alveolar/cirurgia , Animais , Substitutos Ósseos/uso terapêutico , Durapatita , Masculino , Mandíbula/cirurgia , Ratos , Cicatrização
12.
Acta cir. bras ; 34(11): e201901101, Nov. 2019. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1054681

RESUMO

Abstract Purpose: To determine the efficacy of norbixin-based poly(hydroxybutyrate) (PHB) membranes for Achilles tendon repair. Methods: Thirty rats were submitted to total tenotomy surgery of the right Achilles tendon and divided into two groups (control and membrane; n = 15 each), which were further subdivided into three subgroups (days 7, 14, and 21; n = 5 each). Samples were analyzed histologically. Results: Histological analysis showed a significant reduction in inflammatory infiltrates on days 7, 14 (p < 0.0001 for both), and 21 (p = 0.0004) in the membrane group compared to that in the control group. There was also a significant decrease in the number of fibroblasts in the control group on days 7, 14 (p < 0.0001), and 21 (p = 0.0032). Further, an increase in type I collagen deposition was observed in the membrane group compared to that in the control group on days 7 (p = 0.0133) and 14 (p = 0.0107). Conclusion: Treatment with norbixin-based PHB membranes reduces the inflammatory response, increases fibroblast proliferation, and improves collagen production in the tendon repair region, especially between days 7 and 14.


Assuntos
Humanos , Animais , Masculino , Poliésteres/farmacologia , Tendão do Calcâneo/cirurgia , Tendão do Calcâneo/efeitos dos fármacos , Carotenoides/farmacologia , Tenotomia/métodos , Hidroxibutiratos/farmacologia , Valores de Referência , Regeneração/efeitos dos fármacos , Tendão do Calcâneo/patologia , Reprodutibilidade dos Testes , Ratos Wistar , Colágeno Tipo I/análise , Colágeno Tipo I/efeitos dos fármacos , Colágeno Tipo III/análise , Colágeno Tipo III/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos
13.
Med Sci Monit ; 25: 7361-7369, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31570688

RESUMO

BACKGROUND This study aimed to investigate a rabbit model of osteochondral regeneration using three-dimensional (3-D) printed polycaprolactone-hydroxyapatite (PCL-HA) scaffolds coated with umbilical cord blood mesenchymal stem cells (UCB-MSCs) and chondrocytes. MATERIAL AND METHODS Nine female New Zealand white rabbits were included in the study. The 3-D PCL-HA scaffolds were prepared using fused deposition modeling 3-D printing technology. Seeding cells were prepared by co-culture of rabbit UCB-MSCs and chondrocytes with a ratio of 3: 1. A total of 4×106 cells were seeded on 3-D PCL-HA scaffolds and implanted into rabbits with femoral trochlear defects. After 8 weeks of in vivo implantation, 12 specimens were sampled and examined using histology and scanning electron microscopy (SEM). The International Cartilage Repair Society (ICRS) macroscopic scores and histological results were recorded and compared with those of the unseeded PCL-HA scaffolds. RESULTS Mean ICRS scores for the UCB-MSCs and chondrocyte-seeded PCL-HA scaffolds (group A) were significantly higher than the normal unseeded control (NC) PCL-HA scaffold group (group B) (P<0.05). Histology with safranin-O and fast-green staining showed that the UCB chondrocyte-seeded PCL-HA scaffolds significantly promoted bone and cartilage regeneration. CONCLUSIONS In a rabbit model of osteochondral regeneration using 3-D printed PCL-HA scaffolds, the UCB chondrocyte-seeded PCL-HA scaffold promoted articular cartilage repair when compared with the control or non-seeded PCL-HA scaffolds.


Assuntos
Condrócitos/transplante , Transplante de Células-Tronco de Sangue do Cordão Umbilical/métodos , Osteocondrite/terapia , Animais , Materiais Biocompatíveis , Osso e Ossos , Cartilagem Articular/fisiologia , China , Condrócitos/fisiologia , Durapatita/farmacologia , Feminino , Células-Tronco Mesenquimais/fisiologia , Modelos Animais , Poliésteres/farmacologia , Impressão Tridimensional , Coelhos , Engenharia Tecidual/métodos , Tecidos Suporte
14.
Colloids Surf B Biointerfaces ; 184: 110525, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31585307

RESUMO

The purpose of this paper was to fabricate a novel methoxy poly(ethylene glycol)-block-poly(caprolactone)-block-poly(1, 4, 8-Trioxa [4.6] spiro-9-undecanone) (mPEG-b-PCL-b-PTOSUO, mPECT) triblock copolymer and study on the in vitro anti-tumor activity of curcumin-loaded mPECT nanoparticles (NPs). The mPEG-b-PCL-b-PTOSUO NPs were fabricated with solvent evaporation. Transmission electron microscope (TEM) and laser particle analyzer were applied to investigate the morphology and size distribution of the obtained mPECT NPs. The cytotoxicity of the copolymer (mPECT) was reflected by cell viability. Curcumin (CUR), as a model drug, was encapsulated into mPECT NPs. The in vitro anti-tumor activity of CUR-loaded mPECT NPs were also studied. 1H nuclear magnetic resonance (1H NMR), Raman, and Fourier transform infrared spectroscopy (FTIR) spectra confirmed the obtaining of mPECT. TEM photograph showed that most of mPECT NPs were in spherical shapes with a uniform size distribution. High cell viability suggested that the cargo-free mPECT NPs had no obvious cytotoxicity. Fluorescent photographs illustrated that CUR-loaded mPECT NPs could be up-taken by SW1990 cells. The medicated NPs could inhibit the proliferation of SW1990 cells. Therefore, the mPECT NPs could be used as a vehicle to improve the bioavailability and anti-tumor effects of CUR.


Assuntos
Antineoplásicos/farmacologia , Curcumina/farmacologia , Nanopartículas/química , Poliésteres/farmacologia , Polietilenoglicóis/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Curcumina/química , Ensaios de Seleção de Medicamentos Antitumorais , Células Hep G2 , Humanos , Estrutura Molecular , Tamanho da Partícula , Poliésteres/química , Polietilenoglicóis/química , Propriedades de Superfície , Células Tumorais Cultivadas
15.
Biomater Sci ; 7(12): 4912-4943, 2019 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-31576820

RESUMO

Implantable tubular devices known as nerve guidance conduits (NGCs) have drawn considerable interest as an alternative to autografting in the repair of peripheral nerve injuries. At present, there exists a lack of biodegradable, biocompatible materials for the fabrication of NGCs with physical properties which suitably match the native nerve tissue. Most of the existing reports have been confined to the traditional synthetic aliphatic polyesters due to their naturally-occurring degradation by-products, suitably slow in vivo resorption timeframes and relatively diverse and tailorable range of material properties. Moreover, these thermoplastic polymers can be processed into NGCs from various methods and further tweaking of physical properties can be achieved during fabrication. Although there have been many successful reports of nerve gap repair using NGCs made from these materials, the majority have been confined to basic tubular designs across short to medium nerve gaps with at best equivalent outcomes to autografts. This article reviews the performance of poly-α-hydroxyester tubes to date (including modifications to basic hollow conduits) and is intended to aid researchers as they aim to create biomimetic NGCs capable of bridging larger nerve gaps with superior results to autografting. Based on the existing reports, a next-generation bioresorbable NGC should involve a highly flexible poly-α-hydroxyester outer tube, most suitably from a lactide-caprolactone co-polymer, with some combination of internal lumen contact guidance and bioactive neurotrophic factors. However, detailed further experimentation and an interdisciplinary approach will be required to arrive at an ideal final configuration.


Assuntos
Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Regeneração Tecidual Guiada/métodos , Nervos Periféricos/efeitos dos fármacos , Poliésteres/química , Poliésteres/farmacologia , Animais , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/metabolismo , Humanos , Nervos Periféricos/citologia , Nervos Periféricos/fisiologia , Permeabilidade , Poliésteres/síntese química , Poliésteres/metabolismo , Porosidade
16.
Nanoscale ; 11(37): 17211-17215, 2019 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-31531437

RESUMO

Herein, we report a non-cationic DNA-crosslinked nanogel for intracellular delivery of a Cas9 and single guide RNA (Cas9/sgRNA) complex. A DNA-grafted polycaprolactone brush (DNA-g-PCL) is first loaded with the Cas9/sgRNA complex and then crosslinked by DNA linkers via nucleic acid hybridization to form a nanosized hydrogel, in which the gene editing tools are embedded and protected inside. With compact architecture, the Cas9/sgRNA complex-containing nanogel exhibited excellent physiological stability against nuclease digestion and enhanced cellular uptake efficiency, making the delivery system a promising tool for target genome editing.


Assuntos
Sistemas CRISPR-Cas , DNA/química , Edição de Genes , Técnicas de Transferência de Genes , Nanogéis/química , Células HeLa , Humanos , Poliésteres/química , Poliésteres/farmacologia
17.
ACS Appl Mater Interfaces ; 11(41): 37381-37396, 2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31517483

RESUMO

Biodegradable synthetic scaffolds hold great promise for oral and craniofacial guided tissue regeneration and bone regeneration. To overcome the limitations of current scaffold materials in terms of osteogenic and antimicrobial properties, we have developed a novel silver-modified/collagen-coated electrospun poly-lactic-co-glycolic acid/polycaprolactone (PLGA/PCL) scaffold (PP-pDA-Ag-COL) with improved antimicrobial and osteogenic properties. Our novel scaffold was generated by electrospinning a basic PLGA/PCL matrix, followed by silver nanoparticles (AgNPs) impregnation via in situ reduction, polydopamine coating, and then coating by collagen I. The three intermediate materials involved in the fabrication of our scaffolds, namely, PLGA/PCL (PP), PLGA/PCL-polydopamine (PP-pDA), and PLGA/PCL-polydopamine-Ag (PP-pDA-Ag), were used as control scaffolds. Scanning electron micrographs and mechanical testing indicated that the unique three-dimensional structures with randomly oriented nanofibrous electrospun scaffold architectures, the elasticity modulus, and the tensile strength were maintained after modifications. CCK-8 cell proliferation analysis demonstrated that the PP-pDA-Ag-COL scaffold was associated with higher MC3T3 proliferation rates than the three control scaffolds employed. Scanning electron and fluorescence light microscopy illustrated that PP-pDA-Ag-COL scaffolds significantly enhanced MC3T3 cell adhesion compared to the control scaffolds after 12 and 24 h culture, in tandem with the highest ß1 integrin expression levels, both at the mRNA level and the protein level. Alkaline phosphatase activity, BMP2, and RUNX2 expression levels of MC3T3 cells cultured on PP-pDA-Ag-COL scaffolds for 7 and 14 days were also significantly higher when compared to controls (P < 0.001). There was a wider antibacterial zone associated in PP-pDA-Ag-COL and PP-pDA-Ag scaffolds versus control scaffolds (P < 0.05), and bacterial fluorescence was reduced on the Ag-modified scaffolds after 24 h inoculation against Staphylococcus aureus and Streptococcus mutans. In a mouse periodontal disease model, the PP-pDA-Ag-COL scaffold enhanced alveolar bone regeneration (31.8%) and was effective for periodontitis treatment. These results demonstrate that our novel PP-pDA-Ag-COL scaffold enhanced biocompatibility and osteogenic and antibacterial properties and has therapeutic potential for alveolar/craniofacial bone regeneration.


Assuntos
Antibacterianos , Regeneração Óssea/efeitos dos fármacos , Materiais Revestidos Biocompatíveis , Teste de Materiais , Osteogênese/efeitos dos fármacos , Periodontite/terapia , Staphylococcus aureus/crescimento & desenvolvimento , Streptococcus mutans/crescimento & desenvolvimento , Tecidos Suporte/química , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Linhagem Celular , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologia , Colágeno/química , Colágeno/farmacologia , Modelos Animais de Doenças , Regeneração Tecidual Guiada , Camundongos , Periodontite/patologia , Poliésteres/química , Poliésteres/farmacologia , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/farmacologia , Prata/metabolismo , Prata/farmacologia
18.
Colloids Surf B Biointerfaces ; 184: 110506, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31541892

RESUMO

Nanofibrous membranes which exhibit bacteriostatic functions are a good strategy to prevent microorganisms from adhering to the surface of biomaterials. Here, we report the synthesis of such a nanofibrous membrane which can be applied to biological coatings to reduce bacteriostatic functionality. Ascorbic acid was utilized to reduced chloroauric acid to gold nanoparticles (AuNPs). Dopamine was then polymerized upon AuNP surfaces by ultrasound-assistance, to synthesize core-shell structured polydopamine-coated AuNPs (Au@PDA NPs). The Au@PDA NPs were then mixed with polylactic acid (PLA) for electrospinning into cylindrical nanofibers (136.6 nm diameter). PLA-Au@PDA nanofibrous membranes were finally immersed in silver nitrate for in situ reduction into a silver nanoparticle (AgNP) coating to yield PLA-Au@PDA@Ag nanofibers. The PLA-Au@PDA@Ag nanofibers were characterized based on field emission scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and contact angle analyses. The antibacterial properties of the PLA-Au@PDA@Ag nanofibers were examined based on the optical density absorbance of bacterial cell suspensions, traditional colony plate counts, zone inhibition analyses, and field-emission scanning electron microscopy. Escherichia coli and Staphylococcus aureaus respectively served as Gram negative and positive bacterial models of industrial relevance. The data conclusively illustrates the antimicrobial and biomedical applications of PLA-Au@PDA@Ag nanofibers.


Assuntos
Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Indóis/farmacologia , Nanopartículas Metálicas/química , Nanofibras/química , Poliésteres/farmacologia , Polímeros/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/química , Ouro/química , Ouro/farmacologia , Indóis/química , Testes de Sensibilidade Microbiana , Tamanho da Partícula , Poliésteres/química , Polímeros/química , Prata/química , Prata/farmacologia , Propriedades de Superfície
19.
ACS Appl Mater Interfaces ; 11(38): 34560-34574, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31502820

RESUMO

Surface-functionalized microparticles are relevant to fields spanning engineering and biomedicine, with uses ranging from cell culture to advanced cell delivery. Varying topographies of biomaterial surfaces are also being investigated as mediators of cell-material interactions and subsequent cell fate. To investigate competing or synergistic effects of chemistry and topography in three-dimensional cell cultures, methods are required to introduce these onto microparticles without modification of their underlying morphology or bulk properties. In this study, a new approach for surface functionalization of poly(lactic acid) (PLA) microparticles is reported that allows decoration of the outer shell of the polyesters with additional polymers via aqueous atom transfer radical polymerization routes. PLA microparticles with smooth or dimpled surfaces were functionalized with poly(poly(ethylene glycol) methacrylate) and poly[N-(3-aminopropyl)methacrylamide] brushes, chosen for their potential abilities to mediate cell adhesion. X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry analysis indicated homogeneous coverage of the microparticles with polymer brushes while maintaining the original topographies. These materials were used to investigate the relative importance of surface chemistry and topography both on the formation of human immortalized mesenchymal stem cell (hiMSCs) particle-cell aggregates and on the enhanced contractility of cardiomyocytes derived from human-induced pluripotent stem cells (hiPSC-CMs). The influence of surface chemistry was found to be more important on the size of particle-cell aggregates than topographies. In addition, surface chemistries that best promoted hiMSC attachment also improved hiPSC-CM attachment and contractility. These studies demonstrated a new route to obtain topo-chemical combinations on polyester-based biomaterials and provided clear evidence for the predominant effect of surface functionality over micron-scale dimpled topography in cell-microparticle interactions. These findings, thus, provide new guiding principles for the design of biomaterial interfaces to direct cell function.


Assuntos
Diferenciação Celular , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Mesenquimais/metabolismo , Microplásticos , Miócitos Cardíacos/metabolismo , Poliésteres , Agregação Celular/efeitos dos fármacos , Linhagem Celular Transformada , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Mesenquimais/citologia , Microplásticos/química , Microplásticos/farmacologia , Miócitos Cardíacos/citologia , Poliésteres/química , Poliésteres/farmacologia
20.
Mater Sci Eng C Mater Biol Appl ; 104: 109929, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31500017

RESUMO

The clinical application of composites seeks to exploit the mechanical and chemical properties of materials which make up the composite, and in researching polymer composites for biomedical applications the aim is usually to enhance the bioactivity of the polymer, while maintaining the mechanical properties. To that end, in this study medical grade Poly(L-lactic) acid (PLLA) has been reinforced with short phosphate-based glass fibers (PGF). The materials were initially mixed by melting PLLA granules with the short fibers, before being extruded to form a homogenous filament, which was pelletized and used as feedstock for compression moulding. As made the composite materials had a bending strength of 51 MPa ±â€¯5, and over the course of eight weeks in PBS the average strength of the composite material was in the range 20-50 MPa. Human mesenchymal stromal cells were cultured on the surfaces of scaffolds, and the metabolic activity, alkaline phosphatase production and mineralization monitored over a three week period. The short fiber filler made no significant difference to cell proliferation or differentiation, but had a clear and immediate osteoinductive effect, promoting mineralization by cells at the material surface. It is concluded that the PLLA/PGF composite material offers a material with both the mechanical and biological properties for potential application to bone implants and fixation, particularly where an osteoinductive effect would be valuable.


Assuntos
Calcificação Fisiológica/efeitos dos fármacos , Vidro/química , Fosfatos/farmacologia , Poliésteres/farmacologia , Bioensaio , Adesão Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Humanos , Concentração de Íons de Hidrogênio , Íons , Osteogênese/efeitos dos fármacos , Espectroscopia de Prótons por Ressonância Magnética , Difração de Raios X
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA