RESUMO
Amphiphilic copolymers with pendant functional groups in polyester segments are widely used in nanomedicine. These enriched functionalities are designed to form covalent conjugates with payloads or provide additional stabilization effects for encapsulated drugs. A general method is successfully developed for the efficient preparation of functional biodegradable PEG-polyester copolymers via click chemistry. Firstly, in the presence of mPEG as initiator, Sn(Oct)2-catalyzed ring-opening polymerization of the α-alkynyl functionalized lactone with D,L-lactide or ε-caprolactone afforded linear mPEG-polyesters bearing multiple pendant alkynyl groups. Kinetic studies indicated the formation of random copolymers. Through copper-catalyzed azide-alkyne cycloaddition reaction, various small azido molecules with different functionalities to polyester segments are efficiently grafted. The molecular weights, polydispersities and grafting efficiencies of azido molecules of these copolymers were investigated by NMR and GPC. Secondly, it is demonstrated that the resulting amphiphilic functional copolymers with low CMC values could self-assemble to form nanoparticles in aqueous media. In addition, the in vitro degradation study and cytotoxicity assays indicated the excellent biodegradability and low cytotoxicity of these copolymers. This work provides a general approach toward the preparation of functional PEG-polyester copolymers in a quite efficient way, which may further facilitate the application of functional PEG-polyesters as drug delivery materials.
Assuntos
Plásticos Biodegradáveis , Química Click , Sistemas de Liberação de Medicamentos , Poliésteres , Polietilenoglicóis/química , Plásticos Biodegradáveis/síntese química , Plásticos Biodegradáveis/química , Plásticos Biodegradáveis/farmacocinética , Plásticos Biodegradáveis/farmacologia , Catálise , Células HeLa , Humanos , Poliésteres/síntese química , Poliésteres/química , Poliésteres/farmacocinética , Poliésteres/farmacologia , Compostos de Estanho/químicaRESUMO
The microbial biodegradation of new PLA and PCL materials containing birch tar (1-10% v/v) was investigated. Product of dry distillation of birch bark (Betula pendula Roth) was added to polymeric materials to obtain films with antimicrobial properties. The subject of the study was the course of enzymatic degradation of a biodegradable polymer with antibacterial properties. The results show that the type of the material, tar concentration, and the environment influenced the hydrolytic activity of potential biofilm degraders. In the presence of PCL films, the enzyme activities were higher (except for α-D-glucosidase) compared to PLA films. The highest concentration of birch tar (10% v/v) decreased the activity of hydrolases produced by microorganisms to the most significant extent; however, SEM analysis showed the presence of a biofilm even on plastics with the highest tar content. Based on the results of the biological oxygen demand (BOD), the new materials can be classified as biodegradable but, the biodegradation process was less efficient when compared to plastics without the addition of birch tar.
Assuntos
Anti-Infecciosos/química , Betula/química , Plásticos Biodegradáveis/química , Poliésteres/química , Alcatrões/química , Aminopeptidases/metabolismo , Anti-Infecciosos/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/enzimologia , Betula/microbiologia , Plásticos Biodegradáveis/farmacologia , Biofilmes , Análise da Demanda Biológica de Oxigênio , Destilação , Ensaios Enzimáticos , Esterases/metabolismo , Lipase/metabolismo , Casca de Planta/química , Casca de Planta/microbiologia , Poliésteres/metabolismo , Alcatrões/farmacologia , alfa-Glucosidases/metabolismo , beta-Glucosidase/metabolismoRESUMO
Due to its excellent bone-like mechanical properties and non-toxicity, magnesium (Mg) and its alloys have attracted great interest as biomaterials for orthopaedic applications. However, their fast degradation rate in physiological environments leads to an acute inflammatory response, restricting their use as biodegradable metallic implants. Endowing Mg-based biomaterials with immunomodulatory properties can help trigger a desired immune response capable of supporting a favorable healing process. In this study, electrospun poly(ε-caprolactone) (PCL) fibers loaded with coumarin (CM) and/or zinc oxide nanoparticles (ZnO) were used to coat the commercial AZ31 Mg alloy as single and combined formulas, and their effects on the macrophage inflammatory response and osteoclastogenic process were investigated by indirect contact studies. Likewise, the capacity of the analyzed samples to generate reactive oxygen species (ROS) has been investigated. The data obtained by attenuated total reflection Fourier-transform infrared (FTIR-ATR) and X-ray photoelectron spectroscopy (XPS) analyses indicate that AZ31 alloy was perfectly coated with the PCL fibers loaded with CM and ZnO, which had an important influence on tuning the release of the active ingredient. Furthermore, in terms of degradation in phosphate-buffered saline (PBS) solution, the PCL-ZnO- and secondary PCL-CM-ZnO-coated samples exhibited the best corrosion behaviour. The in vitro results showed the PCL-CM-ZnO and, to a lower extent, PCL-ZnO coated sample exhibited the best behaviour in terms of inflammatory response and receptor activator of nuclear factor kappa-B ligand (RANKL)-mediated differentiation of RAW 264.7 macrophages into osteoclasts. Altogether, the results obtained suggest that the coating of Mg alloys with fibrous PCL containing CM and/or ZnO can constitute a feasible strategy for biomedical applications.
Assuntos
Ligas/farmacologia , Inflamação/tratamento farmacológico , Osteogênese/efeitos dos fármacos , Poliésteres/farmacologia , Ligante RANK/genética , Animais , Plásticos Biodegradáveis/química , Plásticos Biodegradáveis/farmacologia , Cumarínicos/química , Cumarínicos/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Imunomodulação/efeitos dos fármacos , Inflamação/genética , Inflamação/patologia , Macrófagos/efeitos dos fármacos , Magnésio/química , Magnésio/farmacologia , Nanopartículas Metálicas/química , Camundongos , Células RAW 264.7 , Espectroscopia de Infravermelho com Transformada de Fourier , Óxido de Zinco/farmacologiaRESUMO
This study aimed to develop an active biodegradable bilayer film and to investigate the release behaviors of active compounds into different food matrices. Cinnamaldehyde (CI) or thymol (Ty) was encapsulated in ß-cyclodextrin (ß-CD) to prepare the active ß-CD inclusion complex (ß-CD-CI/ß-CD-Ty). The tilapia fish gelatin-sodium alginate composite (FGSA) containing ß-CD-CI or ß-CD-Ty was coated on the surface of PLA film to obtain the active bilayer film. Different food simulants including liquid food simulants (water, 3% acetic acid, 10% ethanol, and 95% ethanol), solid dry food simulant (modified polyphenylene oxide (Tenax TA)), and the real food (Japanese sea bass) were selected to investigate the release behaviors of bilayer films into different food matrixes. The results showed that the prepared ß-CD inclusion complexes distributed evenly in the cross-linking structure of FGSA and improved the thickness and water contact angle of the bilayer films. Active compounds possessed the lowest release rates in Tenax TA, compared to the release to liquid simulants and sea bass. CI and Ty sustained the release to the sea bass matrix with a similar behavior to the release to 95% ethanol. The bilayer film containing ß-CD-Ty exhibited stronger active antibacterial and antioxidant activities, probably due to the higher release efficiency of Ty in test mediums.
Assuntos
Acroleína/análogos & derivados , Plásticos Biodegradáveis/química , Embalagem de Alimentos , Timol/química , Acroleína/química , Acroleína/farmacologia , Alginatos/química , Animais , Bass , Plásticos Biodegradáveis/farmacologia , Quitosana/química , Aditivos Alimentares , Microbiologia de Alimentos , Gelatina/química , Poliésteres/química , Poliésteres/farmacologia , Tilápia , Água , beta-Ciclodextrinas/químicaRESUMO
Biodegradable nanostructures displaying aggregation-induced emission (AIE) are desirable from a biomedical point of view, due to the advantageous features of loading capacity, emission brightness, and fluorescence stability. Herein, biodegradable polymers comprising poly (ethylene glycol)-block-poly(caprolactone-gradient-trimethylene carbonate) (PEG-P(CLgTMC)), with tetraphenylethylene pyridinium-TMC (PAIE) side chains have been developed, which self-assembled into well-defined polymersomes. The resultant AIEgenic polymersomes are intrinsically fluorescent delivery vehicles. The presence of the pyridinium moiety endows the polymersomes with mitochondrial targeting ability, which improves the efficiency of co-encapsulated photosensitizers and improves therapeutic index against cancer cells both in vitro and in vivo. This contribution showcases the ability to engineer AIEgenic polymersomes with structure inherent fluorescence and targeting capacity for enhanced photodynamic therapy.
Assuntos
Antineoplásicos/farmacologia , Plásticos Biodegradáveis/farmacologia , Corantes Fluorescentes/farmacologia , Fármacos Fotossensibilizantes/farmacologia , Poliésteres/farmacologia , Polietilenoglicóis/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/efeitos da radiação , Compostos de Benzilideno/síntese química , Compostos de Benzilideno/farmacologia , Compostos de Benzilideno/efeitos da radiação , Plásticos Biodegradáveis/síntese química , Plásticos Biodegradáveis/efeitos da radiação , Compostos de Boro/síntese química , Compostos de Boro/farmacologia , Compostos de Boro/efeitos da radiação , Linhagem Celular Tumoral , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/efeitos da radiação , Humanos , Luz , Fármacos Fotossensibilizantes/síntese química , Fármacos Fotossensibilizantes/efeitos da radiação , Poliésteres/síntese química , Poliésteres/efeitos da radiação , Polietilenoglicóis/síntese química , Polietilenoglicóis/efeitos da radiação , Compostos de Piridínio/síntese química , Compostos de Piridínio/farmacologia , Compostos de Piridínio/efeitos da radiaçãoRESUMO
AIMS: The goal of this study was to evaluate the performance of the InspironTM coronary stent (Scitech Medical™, Goiás, Brazil). The InspironTM sirolimus-eluting stent uses an ultrathin L-605 cobalt-chromium alloy with a 75 µm strut thickness platform coated with an abluminal biodegradable polymer. The polymer is eliminated from the body through the tricarboxylic acid cycle in 6-9 months, releasing 80% of the drug within 30 days after its deployment. METHODS: It was a prospective, single-center registry. To represent clinical practice, all patients undergoing percutaneous coronary intervention were included in this registry. There were no exclusion criteria. Clinical follow-ups were performed at twelve months. The endpoints were the occurrence of all-cause death, definite stent thrombosis, and new revascularization. RESULTS: Between November 2017 and May 2019, 790 patients were included (1067 lesions). The mean age was 60.42 ± 14.94 years, and 74.7% presented with acute coronary syndrome. Diabetes mellitus was present in 43.9% of patients, and previous myocardial infarction and previous percutaneous coronary intervention were present in 17.9% and 11.3%, respectively. Angiographic success was achieved in 99.1%. The incidence of all-cause death was 11.5% (6.2% in-hospital and 5.3% in the follow-up) and definitive stent thrombosis was 0.2%. New revascularization was performed in only 5.8% (target lesion revascularization: 2.2%; progression of disease in another lesion: 3.6%). Based on the multivariate regression analysis, only chronic renal failure was an independent predictor of adverse events (OR: 3.3; 95% CI: 1.22-8.92). CONCLUSION: The result of this single-center registry demonstrates the safety and excellent performance of the InspironTM stent in daily clinical practice with a low rate of adverse cardiac events.
Assuntos
Síndrome Coronariana Aguda , Plásticos Biodegradáveis/farmacologia , Ligas de Cromo/farmacologia , Stents Farmacológicos/efeitos adversos , Intervenção Coronária Percutânea , Sirolimo/farmacologia , Síndrome Coronariana Aguda/mortalidade , Síndrome Coronariana Aguda/cirurgia , Brasil/epidemiologia , Materiais Revestidos Biocompatíveis/farmacologia , Reestenose Coronária/epidemiologia , Reestenose Coronária/etiologia , Reestenose Coronária/cirurgia , Feminino , Humanos , Imunossupressores/farmacologia , Masculino , Pessoa de Meia-Idade , Avaliação de Processos e Resultados em Cuidados de Saúde , Intervenção Coronária Percutânea/efeitos adversos , Intervenção Coronária Percutânea/instrumentação , Intervenção Coronária Percutânea/métodos , Estudos Prospectivos , Desenho de Prótese , Sistema de Registros/estatística & dados numéricos , Reoperação/estatística & dados numéricosRESUMO
Polylactic acid (PLA) films containing 1 wt % and 3 wt % of lignin nanoparticles (pristine (LNP), chemically modified with citric acid (caLNP) and acetylated (aLNP)) were prepared by extrusion and characterized in terms of their overall performance as food packaging materials. Morphological, mechanical, thermal, UV-Vis barrier, antioxidant and antibacterial properties were assayed; appropriate migration values in food simulants and disintegration in simulated composting conditions were also verified. The results obtained indicated that all lignin nanoparticles succeeded in conferring UV-blocking, antioxidant and antibacterial properties to the PLA films, especially at the higher filler loadings assayed. Chemical modification of the fillers partially reduced the UV protection and the antioxidant properties of the resulting composites, but it induced better nanoparticles dispersion, reduced aggregates size, enhanced ductility and improved aesthetic quality of the films through reduction of the characteristic dark color of lignin. Migration tests and disintegration assays of the nanocomposites in simulated composting conditions indicated that, irrespectively of their formulation, the multifunctional nanocomposite films prepared behaved similarly to neat PLA.
Assuntos
Plásticos Biodegradáveis/química , Embalagem de Alimentos , Lignina/química , Nanocompostos/química , Poliésteres/química , Antibacterianos/química , Antibacterianos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Plásticos Biodegradáveis/farmacologia , Compostos de Bifenilo/química , Compostos de Bifenilo/farmacologia , Carbamatos/química , Carbamatos/farmacologia , Ácido Cítrico/química , Ácido Cítrico/farmacologia , Fulerenos/química , Fulerenos/farmacologia , Lignina/farmacologia , Nanocompostos/ultraestrutura , Nanopartículas/química , Nanopartículas/ultraestrutura , Niacinamida/análogos & derivados , Niacinamida/química , Niacinamida/farmacologia , Poliésteres/farmacologia , Pirazóis/química , Pirazóis/farmacologia , Protetores Solares/química , Protetores Solares/farmacologiaRESUMO
The major resolution of the study was to develop a dynamic form of natural biopolymer material to improve the wound healing by inhibition of biofilm formation on the surface. The extraction of collagen was effectively prepared from Scomberomorus lineolatus fish skin. Lyophilized collagen sheet was liquefied in 0.5M acetic acid to form acidic solubilized collagen (ASC) for further analysis. Physicochemical characterization of ASC was performed by various techniques using a standard protocol. The yield of ASC form S.lineolatus is higher (21.5%) than the previous reported studies. The effect of collagen solubility is gradually decreases with increasing concentration of NaCl and collagen is mostly soluble in acidic pH conditions. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of ASC contains α chain composition of α1 and α2 subunits and was characterized as type I collagen. Ultraviolet absorption was regulated as the appropriate wavelength to optimize the collagen. Fourier-transform infrared spectroscopy and X-ray diffraction confirmed that the isolated collagen is a triple-helical structure. The biofilm formation of Pseudomonas aeruginosa was significantly reduced by collagen incorporated with isolated 3,5,7-trihydroxyflavone (collagen-TF) sheet up to 70%. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay executed on fibroblast cell lines (L929) shows that the collagen-TF sheet was 100% compatible to enrich the cell adhesion and proliferation. The current study was the first report to extract, purify, and characterize ASC from S. lineolatus fish skin and characterize as type I collagen. Based on the result, we design the natural biodegradable collagen loaded with TF compound (collagen-TF) for antibiofilm properties. Compared with different sources of polymer, fish skin collagen is more effective and can be used as a biopolymer sheet for wound healing, food, drug delivery, tissue engineering, and pharmaceutical application.
Assuntos
Colágeno Tipo I/farmacologia , Proteínas de Peixes/farmacologia , Pele/química , Cicatrização/efeitos dos fármacos , Animais , Bandagens/microbiologia , Plásticos Biodegradáveis/química , Plásticos Biodegradáveis/farmacologia , Biofilmes/efeitos dos fármacos , Linhagem Celular , Colágeno Tipo I/química , Fibroblastos/efeitos dos fármacos , Proteínas de Peixes/química , Peixes/metabolismo , Humanos , Pele/metabolismo , SolubilidadeRESUMO
The history of resorbable polymers containing glycolide, lactide, ε-caprolactone and trimethylene carbonate, with a special emphasis being placed on the time frame of the 1960s-1990s is described. Reviewing the history is valuable when looking into the future perspectives regarding how and where these monomers should be used. This story includes scientific evaluations indicating that these polymers are safe to use in medical devices, while the design of the medical device is not considered in this report. In particular, we present the data regarding the tissue response to implanted polymers, as well as the toxicity and pharmacokinetics of their degradation products. In the translation of these polymers from "the bench to the bedside," various challenges have been faced by surgeons, medical doctors, biologists, material engineers and polymer chemists. This Perspective highlights the visionary role played by the pioneers, addressing the problems that occurred on a case by case basis in translational medicine.
Assuntos
Materiais Biocompatíveis , Plásticos Biodegradáveis , Teste de Materiais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/história , Materiais Biocompatíveis/farmacologia , Plásticos Biodegradáveis/química , Plásticos Biodegradáveis/história , Plásticos Biodegradáveis/farmacologia , História do Século XX , História do Século XXI , HumanosRESUMO
Synthetic organogels/hydrogels are attracting growing interests due to their potential applications in biomedical fields, organic electronics, and photovoltaics. Photogelation methods for synthesis of organogels/hydrogels have been shown particularly promising because of the high efficiency and simple synthetic procedures. This study synthesized new biodegradable polyhydroxyalkanoates (PHA)-based organogels/hydrogels via UV photo-cross-linking using unsaturated PHA copolymer poly[(R)-3-hydroxyundecanoate-co-(R)-3-hydroxy-10-undecenoate] (PHU10U) with polyethylene glycol dithiol (PDT) as a photo-cross-linker. The PHU10U was synthesized by an engineered Pseudomonas entomophila and characterized via Fourier transform infrared spectroscopy, 1H nuclear magnetic resonance (NMR), and 13C NMR. With decreasing the molar ratio of PHU10U to PDT, both the swelling ratio and pore size were decreased. Meanwhile, increasing densities of the gel networks resulted in a higher compressive modulus. Cell cytotoxicity studies based on the CCK-8 assay on both the PHU10U precursor and PHU10U/PDT hydrogels showed that the novel PHA-based biodegradables acting as hydrogels possess good biocompatibility.
Assuntos
Materiais Biocompatíveis/química , Plásticos Biodegradáveis/química , Hidrogéis/química , Poli-Hidroxialcanoatos/biossíntese , Materiais Biocompatíveis/farmacologia , Materiais Biocompatíveis/efeitos da radiação , Plásticos Biodegradáveis/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Humanos , Hidrogéis/síntese química , Hidrogéis/efeitos da radiação , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Poli-Hidroxialcanoatos/química , Poli-Hidroxialcanoatos/efeitos da radiação , Polímeros/química , Polímeros/efeitos da radiação , Raios Ultravioleta , Ácidos Undecilênicos/química , Ácidos Undecilênicos/efeitos da radiaçãoRESUMO
Poly( R-3-hydroxybutyrate- co- R-3-hydroxyhexanoate) (PHBHHx), a family member of microbial polyhydroxyalkanoates (PHA), is a biodegradable and biocompatible material with some hydrophobicity and reasonable strength for packaging and tissue engineering applications. In this study, superhydrophobic PHBHHx is fabricated via a simple nonsolvent-assisted process. The material can absorb all tested hydrophobic solvents and oil up to 6-fold of the material weights from water, permitting applications for cleaning environmental oil or solvent pollutions with convenience of disposal after the usage due to its biodegradability. With an excellent combination of biodegradability and biocompatibility, superhydrophobic PHBHHx films are evaluated for antibioadhesion properities to exploit possible implant usages. Up to 100% reductions for platelet adhesions on the superhydrophobic PHBHHx surfaces are observed compared with that on the control material surfaces. Superhydrophobic biodegradable and biocompatible PHBHHx films demonstrate promising low value and high volume or high value and low volume applications.
Assuntos
Ácido 3-Hidroxibutírico/química , Materiais Biocompatíveis/química , Plásticos Biodegradáveis/química , Caproatos/química , Adesão Celular , Interações Hidrofóbicas e Hidrofílicas , Ácido 3-Hidroxibutírico/farmacologia , Aderência Bacteriana , Materiais Biocompatíveis/farmacologia , Plásticos Biodegradáveis/farmacologia , Plaquetas/efeitos dos fármacos , Plaquetas/fisiologia , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/fisiologia , Caproatos/farmacologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/fisiologia , Humanos , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/fisiologia , Adesividade Plaquetária , Solventes/químicaRESUMO
Prolonged vaccine release enables gradual immunostimulation, providing long-term immunity. Herein, Vitamin E-PEG-Vitamin E triblock 'ABA' hydrogel, which is formed through physical cross-linking of flower-shaped micelles and can reside in vivo for >17 weeks, was employed for delivery of cancer preventive vaccines to provide sustained anticancer immunity. Mice vaccinated with hydrogel formulations produced a significantly higher quantity of antibodies compared to solution formulations. OVA was used to study EG.7-OVA tumor rejection in vaccinated mice. Among all formulations, OVA-loaded hydrogel containing aluminum-based adjuvant had the best therapeutic outcome, and only 2/10 mice developed solid tumors with significantly smaller tumor size. Moreover, no adverse effect on liver and kidney was detected with the hydrogel formulation. In a lymphoma metastasis mouse model, vaccination with the OVA-loaded hydrogel and adjuvant resulted in increased survival (66.7%) compared to other formulations (12.5-50%) over 100 days. This hydrogel is a promising formulation for sustained delivery of vaccines.
Assuntos
Vacinas Anticâncer/farmacologia , Portadores de Fármacos/farmacologia , Hidrogéis/farmacologia , Imunidade Celular/efeitos dos fármacos , Adjuvantes Imunológicos/química , Adjuvantes Imunológicos/farmacologia , Animais , Plásticos Biodegradáveis/química , Plásticos Biodegradáveis/farmacologia , Vacinas Anticâncer/imunologia , Portadores de Fármacos/química , Humanos , Hidrogéis/química , Rim/efeitos dos fármacos , Fígado/efeitos dos fármacos , Camundongos , Neoplasias/imunologia , Neoplasias/patologia , Neoplasias/terapia , Ovalbumina/efeitos dos fármacos , Ovalbumina/imunologia , Vitamina E/química , Vitamina E/farmacologiaRESUMO
In the present study, the polycaprolactone (PCL) nanofibers were investigated as a carrier to deliver phytochemicals for bone and cartilage tissue engineering. The PCL nanofibers was blended with phytochemicals hexadecanoic acid, octadecanoic acid and N,N-diisopropyl (2,2,3,3,3-pentafluoropropyl) amine isolated from a medicinal plant, Wattakaka volubilis. The scaffolds were characterized using scanning electron microscope (SEM) and Fourier transform infrared (FTIR) spectroscopy. The average diameter of control and phytochemical loaded nanofiber was 208⯱â¯9.6 nm and 316⯱â¯7.0 nm respectively. Biodegradation rate of nanofibers, impact of nanofiber on meniscus and osteoblast cell growth was analyzed using 3-(4,5-dimethyl thiazolyl-2)-2,5-diphenyl tetrazolium bromide (MTT) assay, DNA content and extra cellular matrix secretion. Hoechst stain and SEM images were used to visualize and monitor the cell growth on PCL scaffold. The phytochemicals incorporated PCL nanofibers enhanced the growth and proliferation of primary human meniscus and osteoblast like cells and hence may be suitable scaffold for bone and cartilage tissue engineering applications.
Assuntos
Apocynaceae/química , Regeneração Óssea/efeitos dos fármacos , Menisco/efeitos dos fármacos , Compostos Fitoquímicos/farmacologia , Engenharia Tecidual , Plásticos Biodegradáveis/química , Plásticos Biodegradáveis/farmacologia , Cartilagem/efeitos dos fármacos , Cartilagem/crescimento & desenvolvimento , Linhagem Celular , Humanos , Menisco/crescimento & desenvolvimento , Microscopia Eletrônica de Varredura , Nanofibras/química , Osteoblastos/efeitos dos fármacos , Ácido Palmítico/química , Ácido Palmítico/farmacologia , Compostos Fitoquímicos/química , Poliésteres/química , Poliésteres/farmacologia , Ácidos Esteáricos/química , Ácidos Esteáricos/farmacologiaRESUMO
Polycaprolactone (PCL) was reported a long time ago; however, its biomedical applications has not been extensively investigated in comparison with poly(lactide- co-glycolide) (PLGA) due to its too slow degradation profile. Here, we are reporting an oxalate-connected oligocaprolactone multiblock copolymer (PCL-OX) as a fast degradable PCL while maintaining its crystalline properties and low melting point of PCL. The in vivo application of the paclitaxel-loaded PCL-OX microspheres provided a steady plasma drug concentration of 6-9 µg/mL over 28 days, similar to that of the PLGA microspheres. Both PCL and PLGA microspheres were completely cleared two months after in vivo implantation. The PCL-OX microspheres showed a similar tissue compatibility to that of PLGA microspheres in the subcutaneous layer of rats. These findings suggest that PCL-OX is a useful biomaterial that solves the slow degradation problems of PCL and, thus, may find uses in other biomedical applications as an alternative to PLGA.
Assuntos
Plásticos Biodegradáveis , Sistemas de Liberação de Medicamentos , Microesferas , Paclitaxel , Poliésteres , Animais , Plásticos Biodegradáveis/síntese química , Plásticos Biodegradáveis/química , Plásticos Biodegradáveis/farmacocinética , Plásticos Biodegradáveis/farmacologia , Implantes de Medicamento , Masculino , Paclitaxel/química , Paclitaxel/farmacocinética , Paclitaxel/farmacologia , Poliésteres/química , Poliésteres/farmacocinética , Poliésteres/farmacologia , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/farmacocinética , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/farmacologia , Ratos , Ratos Sprague-DawleyRESUMO
Six guanidine functionalized aliphatic biodegradable polycarbonates with varying molecular weights and charge densities were synthesized via postsynthesis modification of alkyne containing polycarbonates using Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) click chemistry. The concept of passive diluting group was to modify the cationic charge density of the polycarbonate without changing its hydrophilicity. Within the molecular weight range from 8000 to 30000 g mol-1, these guanidine polycarbonates exhibited broad-spectrum biocidal activity with low toxicity to red blood cells (RBCs). The lowest molecular weight homopolymer sample (PG-8k-100) showed the best antimicrobial activity (MIC = 40 µg/mL against Escherichia coli and MIC = 20 µg/mL against Staphylococcus epidermidis) and least RBC toxicity (0.6% hemolysis at MIC). Within the three guanidine charge densities from 20% to 70%, the low to medium dilution samples (PG-8k-7030 and PG-8k-5050) had no obvious loss in antimicrobial activities compared to the nondiluted control sample PG-8k-100. However, upon further dilution, PG-8k-2080 gave the lowest antimicrobial activity.
Assuntos
Anti-Infecciosos/síntese química , Plásticos Biodegradáveis/síntese química , Animais , Anti-Infecciosos/farmacologia , Plásticos Biodegradáveis/farmacologia , Candida albicans/efeitos dos fármacos , Química Click/métodos , Eritrócitos/efeitos dos fármacos , Guanidina/química , Peso Molecular , Pseudomonas aeruginosa/efeitos dos fármacos , Ovinos , Staphylococcus/efeitos dos fármacos , Eletricidade EstáticaRESUMO
OBJECTIVE: We aimed to assess early neointimal healing by optical coherence tomography (OCT) 3 months after implantation of the ultrathin Orsiro® sirolimus-eluting stent with biodegradable polymer. BACKGROUND: New generations of drug-eluting stents with biodegradable polymer have been developed to avoid the continued vascular irritation of durable polymers. METHODS: In this prospective, open-label study, 34 patients received an Orsiro® sirolimus-eluting stent with biodegradable polymer. In a subgroup of patients (n = 15), the intervention was performed under OCT guidance. All patients underwent OCT-examination at three months. The primary endpoint was 3-month neointimal healing (NIH) score, calculated by weighing the presence of filling defects, malapposed and uncovered struts. Secondary endpoint was maturity of tissue coverage at 3 months. RESULTS: At 3 months, NIH score was 13.7 (5.4-22), covered struts per lesion were 90% (84-97%), malapposed struts were 2.7% (0.8-5.4%) and rate of mature tissue coverage was 47% (42-53%). No target lesion failure occurred up to 12 months. Patients with OCT-guided stent implantation demonstrated a trend toward earlier stent healing as demonstrated by superior NIH scores (angio guided: 17.6% [8.8-26.4]; OCT-guided: 9.8% [4.0-15.5]; mean difference -8, [95%CI: -18.7-2.9], P = 0.123). This group had significantly more covered struts per lesion (angio-guided: 86% [82-90]; 95% [92-99]; mean difference 9% [95%CI: 3-15], P = 0.001). CONCLUSION: The Orsiro® sirolimus-eluting stent with biodegradable polymer shows early vascular healing with a high rate of strut coverage at 3-month follow-up. OCT guided stent implantation had a positive impact on early vascular healing.
Assuntos
Plásticos Biodegradáveis/farmacologia , Stents Farmacológicos , Neointima/diagnóstico por imagem , Sirolimo/farmacologia , Tomografia de Coerência Óptica/métodos , Idoso , Feminino , Humanos , Imunossupressores/farmacologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Resultado do Tratamento , Cicatrização/efeitos dos fármacosRESUMO
Polymer-based piezoelectric biomaterials have already proven their relevance for tissue engineering applications. Furthermore, the morphology of the scaffolds plays also an important role in cell proliferation and differentiation. The present work reports on poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV), a biocompatible, biodegradable, and piezoelectric biopolymer that has been processed in different morphologies, including films, fibers, microspheres, and 3D scaffolds. The corresponding magnetically active PHBV-based composites were also produced. The effect of the morphology on physico-chemical, thermal, magnetic, and mechanical properties of pristine and composite samples was evaluated, as well as their cytotoxicity. It was observed that the morphology does not strongly affect the properties of the pristine samples but the introduction of cobalt ferrites induces changes in the degree of crystallinity that could affect the applicability of prepared biomaterials. Young's modulus is dependent of the morphology and also increases with the addition of cobalt ferrites. Both pristine and PHBV/cobalt ferrite composite samples are not cytotoxic, indicating their suitability for tissue engineering applications.
Assuntos
Plásticos Biodegradáveis/química , Plásticos Biodegradáveis/farmacologia , Técnicas Eletroquímicas , Poliésteres/química , Engenharia Tecidual , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Fenômenos Químicos , Cobalto/química , Compostos Férricos/química , Humanos , Interações Hidrofóbicas e Hidrofílicas , Imãs , Teste de Materiais , Nanopartículas Metálicas/química , Camundongos , Osteoblastos , Porosidade , Alicerces TeciduaisRESUMO
In order to create a tissue-engineered vascular graft we elaborated a matrix consisting of nanofibres of biodegradable polymer L-polylactide. We worked out the methodology of crystallization of the matrix on a rod, making it possible to manufacture specimens possessing strength and deformity characteristics superior to those of native vessels. This was followed by a series of chronic experiments on implanting the elaborated matrix into the abdominal aorta of rats for the duration of up to 16 months. We obtained satisfactory parameters of the patency of the matrices (71%). According to the findings of histological examination, in the course of time there occurred biodegradation of the matrix and formation of a new vascular wall, with no evidence of either inflammation or neointimal hyperplasia in the zone of the anastomoses. Resorption of the polymeric fibres commenced 12 weeks after exposure and completely terminated after 64 weeks. By that time, both neointima and neoadventitia were formed, whose composition and structure were close to those of the native vessel. Insufficiently high mechanical properties of the zone of reconstruction turned out to be the cause of the formation of aneurysms.
Assuntos
Aorta Abdominal , Prótese Vascular , Poliésteres/farmacologia , Animais , Aorta Abdominal/patologia , Aorta Abdominal/cirurgia , Plásticos Biodegradáveis/farmacologia , Teste de Materiais/métodos , Nanofibras/uso terapêutico , Ratos , Engenharia Tecidual/métodosRESUMO
Amine-modified four- and eight-armed poloxamines were prepared and subsequently functionalized with maleimide or furyl groups. Aqueous solutions of these polymers exhibited an immediate gelation at a temperature above 37 °C. Concomitantly, Diels-Alder reactions gradually cross-linked and cured the gels. Different ratios between four- and eight-armed macromonomers were used to tune hydrogel stability and mechanical properties. In this way, hydrogel stability could be precisely controlled in the range of 14 to 329 days. Controlled release of the model antibody bevacizumab was achieved over a period of 7, 21, and 115 days. Release profiles were triphasic with a low burst; approximately 87% of the released antibody was intact and displayed functional binding. The hydrogels presented in this study are degradable, nontoxic, rapidly gelling, stable, and provide controlled antibody release. They can be tailored to match the demands of various applications and present an attractive platform for antibody delivery.
Assuntos
Bevacizumab , Plásticos Biodegradáveis , Fibroblastos/metabolismo , Hidrogéis , Animais , Bevacizumab/química , Bevacizumab/farmacocinética , Bevacizumab/farmacologia , Plásticos Biodegradáveis/química , Plásticos Biodegradáveis/farmacocinética , Plásticos Biodegradáveis/farmacologia , Linhagem Celular , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacologia , Fibroblastos/citologia , Hidrogéis/química , Hidrogéis/farmacocinética , Hidrogéis/farmacologia , CamundongosRESUMO
Biodegradable polycarbonate-based ABA triblock copolymers were synthesized via organocatalyzed ring-opening polymerization and successfully formulated into chemically cross-linked hydrogels by strain-promoted alkyne-azide cycloaddition (SPAAC). The synthesis and cross-linking of these polymers are copper-free, thereby eliminating the concern over metallic contaminants for biomedical applications. Gelation occurs rapidly within a span of 60 s by simple mixing of the azide- and cyclooctyne-functionalized polymer solutions. The resultant hydrogels exhibited pronounced shear-thinning behavior and could be easily dispensed through a 22G hypodermic needle. To demonstrate the usefulness of these gels as a drug delivery matrix, doxorubicin (DOX)-loaded micelles prepared using catechol-functionalized polycarbonate copolymers were incorporated into the polymer solutions to eventually form micelle/hydrogel composites. Notably, the drug release rate from the hydrogels was significantly more gradual compared to the solution formulation. DOX release from the micelle/hydrogel composites could be sustained for 1 week, while the release from the micelle solution was completed rapidly within 6 h of incubation. Cellular uptake of the released DOX from the micelle/hydrogel composites was observed at 3 h of incubation of human breast cancer MDA-MB-231 cells. A blank hydrogel containing PEG-(Cat)12 micelles showed almost negligible toxicity on MDA-MB-231cells where cell viability remained high at >80% after treatment. When the cells were treated with the DOX-loaded micelle/hydrogel composites, there was a drastic reduction in cell viability with only 25% of cells surviving the treatment. In all, this study introduces a simple method of formulating hydrogel materials with incorporated micelles for drug delivery applications.