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1.
Molecules ; 26(12)2021 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-34207426

RESUMO

Innovations in food and drink packaging result mainly from the needs and requirements of consumers, which are influenced by changing global trends. Antimicrobial and active packaging are at the forefront of current research and development for food packaging. One of the few natural polymers on the market with antimicrobial properties is biodegradable and biocompatible chitosan. It is formed as a result of chitin deacetylation. Due to these properties, the production of chitosan alone or a composite film based on chitosan is of great interest to scientists and industrialists from various fields. Chitosan films have the potential to be used as a packaging material to maintain the quality and microbiological safety of food. In addition, chitosan is widely used in antimicrobial films against a wide range of pathogenic and food spoilage microbes. Polylactic acid (PLA) is considered one of the most promising and environmentally friendly polymers due to its physical and chemical properties, including renewable, biodegradability, biocompatibility, and is considered safe (GRAS). There is great interest among scientists in the study of PLA as an alternative food packaging film with improved properties to increase its usability for food packaging applications. The aim of this review article is to draw attention to the existing possibilities of using various components in combination with chitosan, PLA, or bacteriocins to improve the properties of packaging in new food packaging technologies. Consequently, they can be a promising solution to improve the quality, delay the spoilage of packaged food, as well as increase the safety and shelf life of food.


Assuntos
Antibacterianos/química , Bacteriocinas/química , Plásticos Biodegradáveis/química , Polímeros/química , Animais , Quitina/química , Quitosana/química , Embalagem de Alimentos/métodos , Humanos , Poliésteres/química
2.
Int J Nanomedicine ; 16: 4351-4369, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34234430

RESUMO

Purpose: Multifunctional nanoparticles with targeted therapeutic function and diagnostic-imaging are of great interest in the domain of precision therapy. NIR laser responsive nanoparticles (PLGA-PEG-FA encapsulating Bi2S3, PFP, and Dox (designed as FBPD NPs)) are synthesized for ovarian cancer targeted combination therapy with CT/PA dual-modal imaging guidance (PA: photoacoustic; CT: X-ray computed tomography). Methods and Results: The FBPD NPS prepared by the double emulsification method revealed excellent dispersity, great stability, outstanding optical properties. The temperature of FBPD NPs increased rapidly after laser irradiation, inducing liquid-to-gas conversion of perfluoropentane (PFP), and promoting the release of Dox up to 86.7%. These FBPD NPs demonstrated their outstanding imaging capability for both PA and CT imaging both in vitro and in vivo, providing the potential for therapeutic guidance and monitoring. Assisted by folic acid, these nanoparticles could highly enrich in ovarian tumor tissue and the accumulation peaked at 3 h after intravenous administration. The desirable photothermal-conversion efficiency of the nanoparticles combined with chemotherapy achieved highly efficient therapy, which was demonstrated both in vitro and in vivo. Conclusion: We successfully constructed multifunctional theranostic FBPD NPs for highly efficient PTT/chemotherapy combined therapy with dual CT/PA imaging guidance/monitoring. The unique nanoparticles with multiple abilities pave an emerging way toward precise treatment of ovarian cancer.


Assuntos
Raios Infravermelhos , Lasers , Nanopartículas/uso terapêutico , Neoplasias Ovarianas/diagnóstico por imagem , Neoplasias Ovarianas/terapia , Técnicas Fotoacústicas , Tomografia Computadorizada por Raios X , Animais , Terapia Combinada , Feminino , Ácido Fólico/química , Humanos , Nanopartículas/química , Poliésteres/química , Polietilenoglicóis/química
3.
Int J Mol Sci ; 22(12)2021 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-34208563

RESUMO

Bone exhibits piezoelectric properties. Thus, electrical stimulations such as pulsed electromagnetic fields (PEMFs) and stimuli-responsive piezoelectric properties of scaffolds have been investigated separately to evaluate their efficacy in supporting osteogenesis. However, current understanding of cells responding under the combined influence of PEMF and piezoelectric properties in scaffolds is still lacking. Therefore, in this study, we fabricated piezoelectric scaffolds by functionalization of polycaprolactone-tricalcium phosphate (PCL-TCP) films with a polyvinylidene fluoride (PVDF) coating that is self-polarized by a modified breath-figure technique. The osteoinductive properties of these PVDF-coated PCL-TCP films on MC3T3-E1 cells were studied under the stimulation of PEMF. Piezoelectric and ferroelectric characterization demonstrated that scaffolds with piezoelectric coefficient d33 = -1.2 pC/N were obtained at a powder dissolution temperature of 100 °C and coating relative humidity (RH) of 56%. DNA quantification showed that cell proliferation was significantly enhanced by PEMF as low as 0.6 mT and 50 Hz. Hydroxyapatite staining showed that cell mineralization was significantly enhanced by incorporation of PVDF coating. Gene expression study showed that the combination of PEMF and PVDF coating promoted late osteogenic gene expression marker most significantly. Collectively, our results suggest that the synergistic effects of PEMF and piezoelectric scaffolds on osteogenesis provide a promising alternative strategy for electrically augmented osteoinduction. The piezoelectric response of PVDF by PEMF, which could provide mechanical strain, is particularly interesting as it could deliver local mechanical stimulation to osteogenic cells using PEMF.


Assuntos
Fosfatos de Cálcio , Materiais Revestidos Biocompatíveis , Campos Eletromagnéticos , Osteogênese , Poliésteres , Polivinil , Tecidos Suporte , Regeneração Óssea , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Materiais Revestidos Biocompatíveis/química , Expressão Gênica , Osteogênese/efeitos dos fármacos , Osteogênese/genética , Osteogênese/efeitos da radiação , Poliésteres/química , Poliésteres/farmacologia , Polivinil/química , Solventes , Engenharia Tecidual , Difração de Raios X
4.
Int J Nanomedicine ; 16: 4321-4332, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34211273

RESUMO

Background: As commonly bone defect is a disease of jaw that can seriously affect implant restoration, the bioactive scaffold can be used as potential systems to provide effective repair for bone defect. Purpose: A osteoinductive bone tissue engineering scaffold has been prepared in order to explore the effect of bioactive materials on bone tissue engineering. Methods: In this study, NELL-1 nanoparticles (Chi/NNP) and nano hydroxyapatite were incorporated in composite scaffolds by electrospinning and characterized using TEM, SEM, contact angle, tensile tests and in vitro drug release. In vitro biological activities such as MC3T3-E1 cell attachment, proliferation and osteogenic activity were studied. Results: With the addition of nHA and nanoparticles, the fiber diameter of PCL/BNPs group, PCL/NNPs group and PCL/nHA/NNPs group was significantly increased. Moreover, the hydrophilic hydroxyl group and amino group presented in nHA and nanoparticles had improved the hydrophilicity of the composite fibers. The composite electrospun containing Chi/NNPs can form a double protective barrier which can effectively prolong the release time of NELL-1 growth factor. In addition, the hydroxyapatite/NELL-1 nanoparticles electrospun fibers can promote attachment, proliferation, differentiation of MC3T3-E1 cells and good cytocompatibility, indicating better ability of inducing osteogenic differentiation. Conclusion: A multi-functional PCL/nHA/NNPs composite fiber with long-term bioactivity and osteoinductivity was successfully prepared by electrospinning. This potential composite could be used as scaffolds in bone tissue engineering application after in vivo studies.


Assuntos
Proteínas de Ligação ao Cálcio/farmacologia , Durapatita/química , Nanofibras/química , Osteogênese/efeitos dos fármacos , Engenharia Tecidual/métodos , Osso e Ossos , Proteínas de Ligação ao Cálcio/química , Proteínas de Ligação ao Cálcio/farmacocinética , Diferenciação Celular/efeitos dos fármacos , Quitosana/química , Liberação Controlada de Fármacos , Humanos , Microscopia Eletrônica de Varredura , Nanopartículas/química , Poliésteres/química , Soroalbumina Bovina/química , Tecidos Suporte
5.
J Med Life ; 14(2): 181-197, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34104241

RESUMO

The present study investigated the capacity of Suprathel® (a copolymer membrane, so far validated for skin regeneration) to also regenerate oral tissue - mucosa and bone, by comparing this biomaterial, in a split-mouth rabbit model, to Mucoderm®, a xenogeneic collagen matrix certified for keratinized oral mucosa healing. The clinical reason behind this experimental animal model was to determine whether the benefits of this advanced skin regeneration product (Suprathel®) could be conveyed for future evaluation in clinical trials of oral tissue regeneration in humans. The outcomes of this study validated the use of Suprathel®, a terpolymer of polylactide with trimethylene carbonate and ε-caprolactone, for stimulation of oral epithelium and alveolar bone regeneration in rabbits. Both Suprathel® and Mucoderm® exhibited comparable results and the null hypothesis stating a comparable regenerating effect of these two materials could not be rejected.


Assuntos
Osso e Ossos/patologia , Epitélio/patologia , Boca/fisiologia , Poliésteres/química , Regeneração , Cicatrização , Animais , Materiais Biocompatíveis/farmacologia , Regeneração Óssea/efeitos dos fármacos , Regeneração Óssea/fisiologia , Osso Esponjoso/patologia , Regeneração Tecidual Guiada , Masculino , Mucosa Bucal/patologia , Neovascularização Fisiológica/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Coelhos , Cicatrização/efeitos dos fármacos
6.
Molecules ; 26(11)2021 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-34073377

RESUMO

Bioactive glasses (BGs) are being increasingly considered for biomedical applications. One convenient approach to utilize BGs in tissue engineering and drug delivery involves their combination with organic biomaterials in order to form composites with enhanced biocompatibility and biodegradability. In this work, mesoporous bioactive glass nanoparticles (MBGN) have been merged with polyhydroxyalkanoate microspheres with the purpose to develop drug carriers. The composite carriers (microspheres) were loaded with curcumin as a model drug. The toxicity and delivery rate of composite microspheres were tested in vitro, reaching a curcumin loading efficiency of over 90% and an improving of biocompatibility of different concentrations of MBGN due to its administrations through the composite. The composite microspheres were tested in terms of controlled release, biocompatibility and bioactivity. Our results demonstrate that the composite microspheres can be potentially used in biomedicine due to their dual effects: bioactivity (due to the presence of MBGN) and curcumin release capability.


Assuntos
Materiais Biocompatíveis/química , Sistemas de Liberação de Medicamentos , Vidro , Nanopartículas/química , Poliésteres/química , Linhagem Celular , Curcumina , Portadores de Fármacos , Durapatita/química , Emulsões , Humanos , Concentração de Íons de Hidrogênio , Cinética , Microscopia Eletrônica de Varredura , Microesferas , Osteoblastos/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Engenharia Tecidual/métodos , Difração de Raios X
7.
Int J Nanomedicine ; 16: 3803-3818, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34113101

RESUMO

Background: Effective repair of full-thickness abdominal wall defects requires a patch with sufficient mechanical strength and anti-adhesion characteristics to avoid the formation of hernias and intra-abdominal complications such as intestinal obstruction and fistula. However, patches made from polymers or bio-derived materials may not meet these requirements and lack the bionic characteristics of the abdominal wall. Materials and Methods: In this study, we report a consecutive electrospun method for preparing a double-layer structured nanofiber membrane (GO-PCL/CS-PCL) using polycaprolactone (PCL), graphene oxide (GO) and chitosan (CS). To expand the bio-functions (angiogenesis/reducing reactive oxygen species) of the patch (GO-PCL/NAC-CS-PCL), N-acetylcysteine (NAC) was loaded for the repair of full-thickness abdominal wall defects (2×1.5cm) in rat model. Results: The double-layered patch (GO-PCL/NAC-CS-PCL) showed excellent mechanical strength and biocompatibility. After 2 months, rats treated with the patch exhibited the desired repair effect with no hernia formation, less adhesion (adhesion score: 1.50±0.50, P<0.001) and more collagen deposition (percentage of collagen deposition: 34.94%±3.31%, P<0.001). Conclusion: The double-layered nanomembranes presented in this study have good anti-hernia and anti-adhesion effects, as well as improve the microenvironment in vivo. It, therefore, holds good prospects for the repair of abdominal wall defects and provides a promising key as a postoperative anti-adhesion agent.


Assuntos
Parede Abdominal/anormalidades , Quitosana/química , Grafite/química , Hérnia/tratamento farmacológico , Nanofibras/administração & dosagem , Poliésteres/administração & dosagem , Aderências Teciduais/tratamento farmacológico , Animais , Colágeno/química , Hérnia/etiologia , Hérnia/patologia , Masculino , Nanofibras/química , Poliésteres/química , Ratos , Ratos Sprague-Dawley , Aderências Teciduais/etiologia , Aderências Teciduais/patologia
8.
Molecules ; 26(9)2021 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-34064416

RESUMO

The objective of this study was to synthesize and characterize a set of biodegradable block copolymers based on TPGS-block-poly(ε-caprolactone) (TPGS-b-PCL) and to assess their self-assembled structures as a nanodelivery system for paclitaxel (PAX). The conjugation of PCL to TPGS was hypothesized to increase the stability and the drug solubilization characteristics of TPGS micelles. TPGS-b-PCL copolymer with various PCL/TPGS ratios were synthesized via ring opening bulk polymerization of ε-caprolactone using TPGS, with different molecular weights of PEG (1-5 kDa), as initiators and stannous octoate as a catalyst. The synthesized copolymers were characterized using 1H NMR, GPC, FTIR, XRD, and DSC. Assembly of block copolymers was achieved via the cosolvent evaporation method. The self-assembled structures were characterized for their size, polydispersity, and CMC using dynamic light scattering (DLS) technique. The results from the spectroscopic and thermal analyses confirmed the successful synthesis of the copolymers. Only copolymers that consisted of TPGS with PEG molecular weights ≥ 2000 Da were able to self-assemble and form nanocarriers of ≤200 nm in diameter. Moreover, TPGS2000-b-PCL4000, TPGS3500-b-PCL7000, and TPGS5000-b-PCL15000 micelles enhanced the aqueous solubility of PAX from 0.3 µg/mL up to 88.4 ug/mL in TPGS5000-b-PCL15000. Of the abovementioned micellar formulations, TPGS5000-b-PCL15000 showed the slowest in vitro release of PAX. Specifically, the PAX-loaded TPGS5000-b-PCL15000 micellar formulation showed less than 10% drug release within the first 12 h, and around 36% cumulative drug release within 72 h compared to 61% and 100% PAX release, respectively, from the commercially available formulation (Ebetaxel®) at the same time points. Our results point to a great potential for TPGS-b-PCL micelles to efficiently solubilize and control the release of PAX.


Assuntos
Portadores de Fármacos/química , Nanopartículas/química , Paclitaxel/farmacologia , Poliésteres/química , Vitamina E/química , Varredura Diferencial de Calorimetria , Cromatografia em Gel , Preparações de Ação Retardada , Liberação Controlada de Fármacos , Micelas , Nanopartículas/ultraestrutura , Tamanho da Partícula , Poliésteres/síntese química , Espectroscopia de Prótons por Ressonância Magnética , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Vitamina E/síntese química , Água/química , Difração de Raios X
9.
Int J Mol Sci ; 22(11)2021 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-34070436

RESUMO

The aim was to examine the efficiency of a scaffold made of poly (L-lactic acid)-co-poly(ϵ-caprolactone), collagen (COL), polyaniline (PANI), and enriched with adipose-derived stem cells (ASCs) as a nerve conduit in a rat model. P(LLA-CL)-COL-PANI scaffold was optimized and electrospun into a tubular-shaped structure. Adipose tissue from 10 Lewis rats was harvested for ASCs culture. A total of 28 inbred male Lewis rats underwent sciatic nerve transection and excision of a 10 mm nerve trunk fragment. In Group A, the nerve gap remained untouched; in Group B, an excised trunk was used as an autograft; in Group C, nerve stumps were secured with P(LLA-CL)-COL-PANI conduit; in Group D, P(LLA-CL)-COL-PANI conduit was enriched with ASCs. After 6 months of observation, rats were sacrificed. Gastrocnemius muscles and sciatic nerves were harvested for weight, histology analysis, and nerve fiber count analyses. Group A showed advanced atrophy of the muscle, and each intervention (B, C, D) prevented muscle mass decrease (p < 0.0001); however, ASCs addition decreased efficiency vs. autograft (p < 0.05). Nerve fiber count revealed a superior effect in the nerve fiber density observed in the groups with the use of conduit (D vs. B p < 0.0001, C vs. B p < 0.001). P(LLA-CL)-COL-PANI conduits with ASCs showed promising results in managing nerve gap by decreasing muscle atrophy.


Assuntos
Modelos Animais de Doenças , Células-Tronco Mesenquimais/metabolismo , Nanofibras/química , Regeneração Nervosa , Neurogênese , Traumatismos dos Nervos Periféricos/terapia , Nervo Isquiático/metabolismo , Tecidos Suporte/química , Compostos de Anilina/química , Animais , Caproatos/química , Células Cultivadas , Colágeno/química , Imuno-Histoquímica , Lactonas/química , Masculino , Teste de Materiais , Células-Tronco Mesenquimais/citologia , Microscopia Eletrônica de Varredura , Músculo Esquelético/citologia , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Nanofibras/ultraestrutura , Traumatismos dos Nervos Periféricos/metabolismo , Traumatismos dos Nervos Periféricos/patologia , Poliésteres/química , Ratos , Ratos Endogâmicos Lew , Nervo Isquiático/citologia , Nervo Isquiático/patologia , Transplante Autólogo
10.
Molecules ; 26(10)2021 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-34064789

RESUMO

Polylactide (PLA) is among the most common biodegradable polymers, with applications in various fields, such as renewable and biomedical industries. PLA features poly(D-lactic acid) (PDLA) and poly(L-lactic acid) (PLLA) enantiomers, which form stereocomplex crystals through racemic blending. PLA emerged as a promising material owing to its sustainable, eco-friendly, and fully biodegradable properties. Nevertheless, PLA still has a low applicability for drug delivery as a carrier and scaffold. Stereocomplex PLA (sc-PLA) exhibits substantially improved mechanical and physical strength compared to the homopolymer, overcoming these limitations. Recently, numerous studies have reported the use of sc-PLA as a drug carrier through encapsulation of various drugs, proteins, and secondary molecules by various processes including micelle formation, self-assembly, emulsion, and inkjet printing. However, concerns such as low loading capacity, weak stability of hydrophilic contents, and non-sustainable release behavior remain. This review focuses on various strategies to overcome the current challenges of sc-PLA in drug delivery systems and biomedical applications in three critical fields, namely anti-cancer therapy, tissue engineering, and anti-microbial activity. Furthermore, the excellent potential of sc-PLA as a next-generation polymeric material is discussed.


Assuntos
Tecnologia Biomédica/métodos , Sistemas de Liberação de Medicamentos , Poliésteres/química , Humanos , Nanopartículas/química , Nanopartículas/ultraestrutura , Estereoisomerismo , Engenharia Tecidual
11.
Int J Mol Sci ; 22(11)2021 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-34063742

RESUMO

Three-dimensional (3D) printing is perceived as an innovative tool for change in tissue engineering and regenerative medicine based on research outcomes on the development of artificial organs and tissues. With advances in such technology, research is underway into 3D-printed artificial scaffolds for tissue recovery and regeneration. In this study, we fabricated artificial scaffolds by coating bone demineralized and decellularized extracellular matrix (bdECM) onto existing 3D-printed polycaprolactone/tricalcium phosphate (PCL/TCP) to enhance osteoconductivity and osteoinductivity. After injecting adipose-derived stem cells (ADSCs) in an aggregate form found to be effective in previous studies, we examined the effects of the scaffold on ossification during mandibular reconstruction in beagle dogs. Ten beagles were divided into two groups: group A (PCL/TCP/bdECM + ADSC injection; n = 5) and group B (PCL/TCP/bdECM; n = 5). The results were analyzed four and eight weeks after intervention. Computed tomography (CT) findings showed that group A had more diffuse osteoblast tissue than group B. Evidence of infection or immune rejection was not detected following histological examination. Goldner trichrome (G/T) staining revealed rich ossification in scaffold pores. ColI, Osteocalcin, and Runx2 gene expressions were determined using real-time polymerase chain reaction. Group A showed greater expression of these genes. Through Western blotting, group A showed a greater expression of genes that encode ColI, Osteocalcin, and Runx2 proteins. In conclusion, intervention group A, in which the beagles received the additional ADSC injection together with the 3D-printed PCL/TCP coated with bdECM, showed improved mandibular ossification in and around the pores of the scaffold.


Assuntos
Tecido Adiposo/citologia , Fosfatos de Cálcio/química , Matriz Extracelular/fisiologia , Mandíbula/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Poliésteres/química , Células-Tronco/citologia , Tecidos Suporte/química , Adipócitos/citologia , Animais , Regeneração Óssea/efeitos dos fármacos , Cães , Osteoblastos/efeitos dos fármacos , Impressão Tridimensional , Engenharia Tecidual/métodos
12.
J Vis Exp ; (170)2021 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-33970145

RESUMO

Polymersomes are membrane-bound, bilayer vesicles created from amphiphilic block copolymers that can encapsulate both hydrophobic and hydrophilic payloads for drug delivery applications. Despite their promise, polymersomes are limited in application due to their spherical shape, which is not readily taken up by cells, as demonstrated by solid nanoparticle scientists. This article describes a salt-based method for increasing the aspect ratios of spherical poly(ethylene glycol) (PEG)- based polymersomes. This method can elongate polymersomes and ultimately control their final shape by adding sodium chloride in post-formation dialysis. Salt concentration can be varied, as described in this method, based on the hydrophobicity of the block copolymer being used as the base for the polymersome and the target shape. Elongated nanoparticles have the potential to better target the endothelium in larger diameter blood vessels, like veins, where margination is observed. This protocol can expand therapeutic nanoparticle applications by utilizing elongation techniques in tandem with the dual-loading, long-circulating benefits of polymersomes.


Assuntos
Pressão Osmótica/fisiologia , Poliésteres/química , Polímeros/química
13.
J Food Sci ; 86(6): 2481-2490, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33948960

RESUMO

The migration study of nano-Ag migration from polylactic acid (PLA) films was studied. Samples treated by high-pressure food processing (0, 100, 200, 300, and 400 MPa pressure) were soaked in acetic acid solution and incubated at 20 °C for 90 days. At the end of storage, nano-Ag particles (AgNPs) migration from the PLA/AgNPs composite film treated under 200 MPa high pressure was the lowest. However, AgNPs migration was accelerated under 400 MPa high pressure. High-pressure processing (200 MPa) could cause denser structure and higher crystallinity degree in films than other treatments. Lower amount of AgNPs induced a decline in the intensity of specific characteristic peaks. The diffraction peak intensity of α-crystal for the film sample treated with 400 MPa was the lowest on day 60. The crystallization index of the PLA matrix changed with different high-pressure processing. The result indicated that appropriate high-pressure food processing could effectively suppress AgNPs migration from PLA-based film while contacting with acidic acid food simulant. PRACTICAL APPLICATION: The release of nanoparticles from food packaging material is a very important matter when the migration is concerned with regulatory and toxicity issues. The study described the migration kinetic of AgNPs from PLA nanocomposite film into acidic food simulant after different high-pressure food processing. The results indicated that the PLA/AgNPs nanocomposite film was safe for acidic food after high-pressure treatment.


Assuntos
Ácidos/análise , Contaminação de Alimentos/análise , Manipulação de Alimentos/métodos , Nanocompostos/química , Poliésteres/química , Pressão , Prata/fisiologia , Ácidos/química , Cinética , Prata/química
14.
Molecules ; 26(7)2021 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-33807351

RESUMO

Poly lactic acid (PLA) is a compostable, as well as recyclable, sustainable, versatile and environmentally friendly alternative, because the monomer of PLA-lactide (LA) is extracted from natural sources. PLA's techno-functional properties are fairly similar to fossil-based polymers; however, in pristine state, its brittleness and delicacy during processing pose challenges to its potential exploitation in diverse food packaging applications. PLA is, therefore, re-engineered to improve its thermal, rheological, barrier and mechanical properties through nanoparticle (NP) reinforcement. This review summarises the studies on PLA-based nanocomposites (PLA NCs) developed by reinforcing inorganic metal/metallic oxide, graphite and silica-based nanoparticles (NPs) that exhibit remarkable improvement in terms of storage modulus, tensile strength, crystallinity, glass transition temperature (Tg) value, antimicrobial property and a decrease in water vapour and oxygen permeability when compared with the pristine PLA films. This review has also discussed the regulations around the use of metal oxide-based NPs in food packaging, PLA NC biodegradability and their applications in food systems. The industrial acceptance of NCs shows highly promising perspectives for the replacement of traditional petrochemical-based polymers currently being used for food packaging.


Assuntos
Antibacterianos , Embalagem de Alimentos , Nanocompostos/química , Poliésteres , Antibacterianos/química , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Plásticos Biodegradáveis , Nanopartículas , Permeabilidade , Poliésteres/química , Poliésteres/farmacologia , Vapor , Resistência à Tração
15.
Int J Mol Sci ; 22(7)2021 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-33800567

RESUMO

Plastic pollution is one of the crucial global challenges nowadays, and biodegradation is a promising approach to manage plastic waste in an environment-friendly and cost-effective way. In this study we identified the strain of fungus Trichoderma viride GZ1, which was characterized by particularly high pectinolytic activity. Using differential scanning calorimetry, Fourier-transform infrared spectroscopy techniques, and viscosity measurements we showed that three-month incubation of polylactide and polyethylene terephthalate in the presence of the fungus lead to significant changes of the surface of polylactide. Further, to gain insight into molecular mechanisms underneath the biodegradation process, western blot hybridization was used to show that in the presence of poly(ethylene terephthalate) (PET) in laboratory conditions the fungus produced hydrophobin proteins. The mycelium adhered to the plastic surface, which was confirmed by scanning electron microscopy, possibly due to the presence of hydrophobins. Further, using atomic force microscopy we demonstrated for the first time the formation of hydrophobin film on the surface of aliphatic polylactide (PLA) and PET by T. viride GZ1. This is the first stage of research that will be continued under environmental conditions, potentially leading to a practical application.


Assuntos
Hypocreales/metabolismo , Plásticos/química , Poliésteres/química , Polietilenotereftalatos/química , Biodegradação Ambiental , Varredura Diferencial de Calorimetria , Microscopia de Força Atômica , Polímeros/química , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Viscosidade , Microbiologia da Água , Poluentes Químicos da Água
16.
Int J Mol Sci ; 22(7)2021 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-33800709

RESUMO

Porous biodegradable scaffolds provide a physical substrate for cells allowing them to attach, proliferate and guide the formation of new tissues. A variety of techniques have been developed to fabricate tissue engineering (TE) scaffolds, among them the most relevant is the thermally-induced phase separation (TIPS). This technique has been widely used in recent years to fabricate three-dimensional (3D) TE scaffolds. Low production cost, simple experimental procedure and easy processability together with the capability to produce highly porous scaffolds with controllable architecture justify the popularity of TIPS. This paper provides a general overview of the TIPS methodology applied for the preparation of 3D porous TE scaffolds. The recent advances in the fabrication of porous scaffolds through this technique, in terms of technology and material selection, have been reviewed. In addition, how properties can be effectively modified to serve as ideal substrates for specific target cells has been specifically addressed. Additionally, examples are offered with respect to changes of TIPS procedure parameters, the combination of TIPS with other techniques and innovations in polymer or filler selection.


Assuntos
Engenharia Tecidual/métodos , Tecidos Suporte/química , Animais , Materiais Biocompatíveis/química , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Poliésteres/química , Polímeros/química , Porosidade , Solventes/química , Temperatura
17.
Mol Biol Rep ; 48(4): 3549-3559, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33866496

RESUMO

This study investigated the differentiation of transplanted transplanted mesenchymal stem cells MSCs into neuron-like cells, repair of erectile dysfunction (ED), and synergy of MSCs seeded to nanofibrous scaffolds with after transplantation around the injured cavernous nerve (CN) of rats. The synthesized polymer was electrospun in a rotating drum to prepare nanofiber meshes (NMs). Human MSCs were prepared and confirmed. Eight-week-old male Sprague-Dawley rats were divided into five groups of six each: group 1-sham operation; group 2-CN injury; group 3-MSCs treatment after CN injury; group 4-nanofibrous scaffold treatment after CN injury; and group 5-post-CN injury treatment combining a nanofibrous scaffold and MSCs (nano-MSCs). In the latter group, the damaged CN was instantly surrounded by an MSC-containing a nanofibrous scaffold in the aftermath of injury. Morphological analysis and immuno-histochemical staining in relation to nerves (Tuj1, NF, MAP2, MBP and peripherin), endothelium (vWF), smooth muscle (SMA), neurofilament (NF), and apoptosis (TUNEL) were performed. We evaluated the mean proportion expressed as a percentage of the ratio of muscle to collagen of penile cavernous smooth-muscle cells as well as the expression of cavernous SMA, NF, vWF, and TUNEL makers. Compared to the group free of CN injury, erectile function was markedly reduced in the group with CN injury at 2 and 4 weeks (p < 0.05). By contrast, compared to the sham operation group, erectile function was better in the group with MSC transplantation (p < 0.05). Similarly, by comparison to the group solely with hMSCs, erectile function was better in the group with nano-MSC transplantation (p < 0.05). Transplantation of MSCs demonstrated the neuronal differentiation. By contrast to MSCs on their own, neuronal differentiation was more significantly expressed in nano-MSCs. The mean proportion expressed as a percentage of the ratio of muscle to collagen of penile cavernous smooth-muscle cells, the expression of cavernous SMA, NF, vWF, and apoptosis improved in the cavernosum after transplantation. NMs showed synergy with MSCs for the repair of erectile dysfunction. Transplanted MSCs differentiated into neuron-like cells and repaired erectile dysfunction in the rats with CN injury. Transplanted MSCs increased the mean percentage of the collagen area of the caversnosum as well as the expression levels of cavernous neuronal, endothelial, smooth-muscle markers, and apoptosis.


Assuntos
Diferenciação Celular , Disfunção Erétil/terapia , Transplante de Células-Tronco Mesenquimais/métodos , Regeneração Nervosa , Traumatismos dos Nervos Periféricos/terapia , Actinas/genética , Actinas/metabolismo , Animais , Apoptose , Células Cultivadas , Humanos , Masculino , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismo , Proteínas de Neurofilamentos/genética , Proteínas de Neurofilamentos/metabolismo , Pênis/inervação , Poliésteres/química , Ratos , Ratos Sprague-Dawley , Tecidos Suporte/química , Tubulina (Proteína)/metabolismo
18.
Int J Mol Sci ; 22(8)2021 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-33924597

RESUMO

Over the past 25 years, cannabis plants have gained major popularity in the research community. This study aimed to evaluate the antioxidant capacity and stabilization efficiency of cannabidiol (CBD) extract in two different polymers: polylactide (PLA) and ethylene-norbornene copolymer (Topas) that are used in packaging materials more often. The research technology included weathering in a special chamber, surface free energy and color change measurements, surface morphology and Fourier-transform infrared spectroscopy (FTIR) analysis, thermogravimetry, and determination of the oxidation induction time or temperature (OIT) values, based on which the effectiveness of the cannabidiol extract could be estimated. Obtained results showed that the addition of CBD to polymer mixtures significantly increased their resistance to oxidation, and it can be used as a natural stabilizer for polymeric products. Moreover, samples with cannabidiol changed their coloration as a result of weathering. Therefore, this natural additive can also be considered as a colorimetric indicator of aging that informs about the changes in polymeric materials during their lifetime. On the other hand, surface properties of samples with cannabidiol content did not alter much compared to pure Topas and PLA.


Assuntos
Plantas/química , Polímeros/química , Embalagem de Produtos , Canabidiol/química , Fenômenos Químicos , Etilenos/química , Norbornanos/química , Fenômenos Ópticos , Oxirredução , Poliésteres/química , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Termogravimetria
19.
Molecules ; 26(5)2021 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-33802604

RESUMO

Electrospun nonwovens of poly(L-lactide) (PLLA) modified with multiwall carbon nanotubes (MWCNT) and linear ladder-like poly(silsesquioxane) with methoxycarbonyl side groups (LPSQ-COOMe) were obtained. MWCNT and LPSQ-COOMe were added to the polymer solution before the electrospinning. In addition, nonwovens of PLLA grafted to modified MWCNT were electrospun. All modified nonwovens exhibited higher tensile strength than the neat PLA nonwoven. The addition of 10 wt.% of LPSQ-COOMe and 0.1 wt.% of MWCNT to PLLA increased the tensile strength of the nonwovens 2.4 times, improving also the elongation at the maximum stress.


Assuntos
Materiais Biocompatíveis/química , Nanocompostos/química , Nanotubos de Carbono/química , Compostos de Organossilício/química , Poliésteres/química , Polímeros/química , Teste de Materiais , Resistência à Tração
20.
J Environ Sci Health B ; 56(5): 467-476, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33852377

RESUMO

Different technologies to prepare long term pesticide forms include polymer coating, preparing composites and encapsulating pesticides in nanoparticles. A simple and low-cost method was proposed to obtain slow-release formulations by co-extrusion of a pesticide with a biodegradable polymer at a temperature above the melting points of both components. A herbicide metribuzin and low-melting polyester poly-ε-caprolactone were chosen for this work. Formulations containing 10%, 20%, and 40% herbicide were prepared. During 7 days of their exposition in water, it was released from 81% to 96% of initially loaded metribuzin; the highest release was detected for 40%-loaded forms. Biodegradation of the constructs and pesticide release were further studied in the model soil. Degradation rates of the specimens increased with an increase in pesticide content, from 9% to 20% over 14 weeks for the 10%/20%-loaded and the 40%-loaded specimens, respectively. The release of metribuzin reached, respectively, 37-38% and 55%. The herbicide content in soil was lower due to its partial degradation in soil; it reached 23-25% and 33%, respectively, from initially loaded into the polymer matrix. Release kinetics of metribuzin in water as in soil best fitted the First-order model. The used approach is promising for obtaining long-term release formulations for soil applications.


Assuntos
Caproatos/química , Herbicidas/química , Lactonas/química , Poliésteres/química , Poluentes do Solo/química , Triazinas/química , Biodegradação Ambiental , Caproatos/análise , Caproatos/farmacocinética , Preparações de Ação Retardada , Composição de Medicamentos , Herbicidas/análise , Herbicidas/farmacocinética , Cinética , Lactonas/análise , Lactonas/farmacocinética , Poliésteres/análise , Poliésteres/farmacocinética , Solo/química , Poluentes do Solo/análise , Poluentes do Solo/farmacocinética , Triazinas/análise , Triazinas/farmacocinética
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