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1.
Int J Mol Sci ; 24(2)2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36674906

RESUMO

In this study, an antibacterial and shape-memory chitosan cryogel with high blood absorption and fast recovery from non-compressible wounds was prepared using a one-step method. Herein, we prepared a shape-memory-reduced graphene/chitosan (rGO-CTS) cryogel using a one-step method with a frozen mixing solution of chitosan, citric acid, dopamine, and graphene oxide, before treating it with alkaline solutions. The alkaline solution not only promoted the double cross-linking of chitosan but also induced dopamine to form polydopamine-reducing graphene oxide. Scanning electron microscope (SEM) images showed that the rGO-CTS cryogel possessed a uniform porous network structure, attributing excellent water-induced shape-memory properties. Moreover, the rGO-CTS cryogel exhibited good mechanical properties, antibacterial activity, and biocompatibility. In mouse liver trauma models, the rGO-CTS cryogel showed good blood clotting and hemostatic capabilities. Therefore, this composite cryogel has great potential as a new hemostatic material for application to non-compressible wounds.


Assuntos
Quitosana , Grafite , Hemostáticos , Camundongos , Animais , Quitosana/química , Grafite/farmacologia , Grafite/química , Criogéis/química , Dopamina , Modelos Animais de Doenças , Antibacterianos/farmacologia
2.
Int J Mol Sci ; 23(22)2022 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-36430295

RESUMO

In this study, a hydrogel composite wound dressing with antibacterial and self-healing ability was prepared using cysteine-modified carboxymethyl chitosan, sodium oxidized alginate, and but-3-yn-2-one base on Schiff base and thiol-alkynone double cross-links. The structure and properties of the hydrogel were characterized by scanning electron microscope, Fourier-transform infrared, and rheological test, followed by antibacterial and in vivo biocompatibility tests. The results showed that the hydrogel exhibited good self-healing, mechanical properties, good antibacterial effect, and in vivo biocompatibility, and can inhibit inflammation and promote skin tissue regeneration in mice. This novel self-healing hydrogel dressing has a broad application prospect in skin tissue engineering.


Assuntos
Surdez , Prunella , Animais , Camundongos , Hidrogéis/farmacologia , Bases de Schiff , Compostos de Sulfidrila , Bandagens , Polissacarídeos/farmacologia , Carboidratos da Dieta , Antibacterianos/farmacologia
3.
Int J Mol Sci ; 23(14)2022 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-35887058

RESUMO

In this study, a photocatalytic antibacterial composite of polydopamine-reduced graphene oxide (PDA-rGO)/BiVO4 is prepared by a hydrothermal self-polymerization reduction method. Its morphology and physicochemical properties are characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Fourier-transform infrared (FT-IR), and X-ray diffraction (XRD). The results indicate that BiVO4 particles are evenly distributed on the rGO surface. Escherichia coli (E. coli) MG1655 is selected as the model bacteria, and its antibacterial performance is tested by flat colony counting and the MTT method under light irradiation. PDA-rGO/BiVO4 inhibits the growth of E. coli under both light and dark conditions, and light significantly enhances the bacteriostasis of PDA-rGO/BiVO4. A combination of BiVO4 with PDA-rGO is confirmed by the above characterization methods as improving the photothermal performance under visible light irradiation. The composite possesses enhanced photocatalytic antibacterial activity. Additionally, the photocatalytic antibacterial mechanism is investigated via the morphology changes in the SEM images of MG1655 bacteria, 2',7'-dichlorofluorescein diacetate (DCFH-DA), the fluorescence detection of the reactive oxygen species (ROS), and gene expression. These results show that PDA-rGO/BiVO4 can produce more ROS and lead to bacterial death. Subsequently, the q-PCR results show that the transmembrane transport of bacteria is blocked and the respiratory chain is inhibited. This study may provide an important strategy for expanding the application of BiVO4 in biomedicine and studying the photocatalytic antibacterial mechanism.


Assuntos
Bismuto , Vanadatos , Antibacterianos/farmacologia , Bismuto/química , Bismuto/farmacologia , Catálise , Escherichia coli , Grafite , Indóis , Luz , Polímeros , Espécies Reativas de Oxigênio , Espectroscopia de Infravermelho com Transformada de Fourier , Vanadatos/farmacologia
4.
Int J Mol Sci ; 22(7)2021 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-33805568

RESUMO

Despite the existence of many attempts at nerve tissue engineering, there is no ideal strategy to date for effectively treating defective peripheral nerve tissue. In the present study, well-aligned poly (L-lactic acid) (PLLA) nanofibers with varied nano-porous surface structures were designed within different ambient humidity levels using the stable jet electrospinning (SJES) technique. Nanofibers have the capacity to inhibit bacterial adhesion, especially with respect to Staphylococcus aureus (S. aureus). It was noteworthy to find that the large nano-porous fibers were less detrimentally affected by S. aureus than smaller fibers. Large nano-pores furthermore proved more conducive to the proliferation and differentiation of neural stem cells (NSCs), while small nano-pores were more beneficial to NSC migration. Thus, this study concluded that well-aligned fibers with varied nano-porous surface structures could reduce bacterial colonization and enhance cellular responses, which could be used as promising material in tissue engineering, especially for neuro-regeneration.


Assuntos
Antibacterianos/farmacologia , Nanofibras/química , Células-Tronco Neurais/citologia , Engenharia Tecidual/métodos , Animais , Antibacterianos/química , Materiais Biocompatíveis/química , Diferenciação Celular , Movimento Celular , Proliferação de Células , Escherichia coli/efeitos dos fármacos , Expressão Gênica , Camundongos , Células-Tronco Neurais/fisiologia , Poliésteres/química , Porosidade , Staphylococcus aureus/efeitos dos fármacos , Engenharia Tecidual/instrumentação , Alicerces Teciduais , Difração de Raios X
5.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 38(8): 749-752, 2021 Aug 10.
Artigo em Zh | MEDLINE | ID: mdl-34365616

RESUMO

OBJECTIVE: To explore the genetic basis for a Chinese patient featuring cleidocranial dysplasia(CCD). METHODS: Genomic DNA was extracted from peripheral blood samples of the patient and his parents. Whole exome sequencing (WES) was carried out for the patient, and suspected variant was verified by Sanger sequencing. RESULTS: WES has identified a missense c.460G>T (p.Val154Phe) (GRCh37/hg19) variant of the RUNX2 gene. The variant was located in the Runt domain, a highly conserved region (PM1); it was not present in either the Genome Aggregation Database or the 1000 Genomes Project (PM2), and was predicted to have a deleterious effect on the gene product by multiple in silico prediction tools (PP3); the clinical phenotype of the patient was highly consistent with that of cleidocranial dysplasia (PP4). Furthermore, the variant was unreported in medical literature and was absent in both parents (PS2). Based on the American College of Medical Genetics and Genomics guidelines, the c.460 G>T variant of RUNX2 gene was predicted to be pathogenic (PS2+PM1+PM2+PP3+PP4). CONCLUSION: The c.460G>T (p.Val154Phe) variant of the RUNX2 gene probably underlay the clinical phenotype in the patient. Above finding has enabled accurate diagnosis and expanded the spectrum of RUNX2 variants.


Assuntos
Displasia Cleidocraniana , China , Displasia Cleidocraniana/genética , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Humanos , Mutação , Sequenciamento do Exoma
6.
FASEB J ; 33(1): 996-1007, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30096039

RESUMO

Blood vessels composed of endothelial cells (ECs) contact with mesenchymal stem cells (MSCs) in different tissues, suggesting possible interaction between these 2 types of cells. We hypothesized that endothelin-1 (ET1), a secreted paracrine factor of ECs, can differentially direct the lineages of adipose-derived stem cells (ASCs) and bone marrow-derived MSCs (BMSCs). Predifferentiated ASCs and BMSCs were treated with ET1 for 2 cell passages and then induced for multilineage differentiation. Our results showed that adipogenesis of ET1-pretreated ASCs and osteogenesis of ET1-pretreated BMSCs were increased compared to those of control cells. The effect of ET1 on enhancing adipogenesis of ASCs and osteogenesis of BMSCs was attenuated by blocking endothelin receptor type A (ETAR) and/or endothelin receptor type B (ETBR). Western blot analysis indicated that regulation by ET1 was mediated through activation of the protein kinase B and ERK1/2 signaling pathways. We analyzed subpopulations of ASCs and BMSCs with or without ETAR and/or ETBR, and we found that ETAR+/ETBR- and ETAR-/ETBR+ subpopulations of ASCs and those of BMSCs pretreated with ET1 were prone to turning into adipocytes and osteoblasts, respectively, after differentiation induction. Our findings provide insight into the differential regulation of MSC specification by ET1, which may help develop viable approaches for tissue regeneration.-Lee, M.-S., Wang, J., Yuan, H., Jiao, H., Tsai, T.-L., Squire, M. W., Li, W.-J. Endothelin-1 differentially directs lineage specification of adipose- and bone marrow-derived mesenchymal stem cells.


Assuntos
Tecido Adiposo/citologia , Células da Medula Óssea/citologia , Endotelina-1/metabolismo , Células-Tronco/citologia , Adulto , Diferenciação Celular , Linhagem da Célula , Proliferação de Células , Células Cultivadas , Feminino , Humanos , Masculino , Osteogênese , Receptores de Endotelina/metabolismo
7.
Cell Biol Int ; 39(1): 65-73, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25052549

RESUMO

We have demonstrated that selected growth factors are involved in regulating survival and proliferation of progenitor cells derived from the neonatal rat organ of Corti (OC). The protective and regenerative effects of these defined growth factors on the injured organ of Corti were therefore investigated. The organ of Corti dissected from the Wistar rat pups (P3-P5) was split into apical, middle, and basal parts, explanted and cultured with or without neomycin and growth factors. Insulin-like growth factor-1 (IGF-1), fibroblast growth factor-2 (FGF-2), and epidermal growth factor (EGF) protected the inner hair cells (IHCs) and outer hair cells (OHCs) from neomycin ototoxicity. Using EGF, IGF-1, and FGF-2 alone induced no protective effect on the survival of auditory hair cells. Combining 2 growth factors (EGF + IGF-1, EGF + FGF-2, or IGF-1 + FGF-2) gave statistically protective effects. Similarly, combining all three growth factors effectively protected auditory hair cells from the ototoxic insult. None of the growth factors induced regeneration of hair cells in the explants injured with neomycin. Thus various combinations of the three defined factors (IGF-1, FGF-2, and EGF) can protect the auditory hair cells from the neomycin-induced ototoxic damage, but no regeneration was seen. This offers a possible novel approach to the treatment of hearing loss.


Assuntos
Fator de Crescimento Epidérmico/farmacologia , Fator 2 de Crescimento de Fibroblastos/farmacologia , Fator de Crescimento Insulin-Like I/farmacologia , Neomicina/toxicidade , Órgão Espiral/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Ciliadas Auditivas/citologia , Órgão Espiral/citologia , Ratos , Ratos Wistar
8.
Int J Biol Macromol ; 269(Pt 2): 131879, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38692527

RESUMO

Multifunctional polysaccharide hydrogels with strong tissue adhesion, and antimicrobial and hemostatic properties are attractive wound healing materials. In this study, a chitosan-based hydrogel (HCS) was designed, and its properties were enhanced by incorporating oxidized eggshell membrane (OEM). Hydrogel characterization and testing results showed that the hydrogel had excellent antimicrobial properties, cytocompatibility, satisfactory adhesion properties on common substrates, and wet-state adhesion capacity. A rat liver injury model confirmed the significant hemostatic effect of the hydrogel. Finally, the ability of the hydrogel to promote wound healing was verified using rat skin wound repair experiments. Our findings indicate that HCS/OEM hydrogels with added eggshell membrane fibers have better self-healing properties, mechanical strength, adhesion, hemostatic properties, and biocompatibility than HCS hydrogels, in addition to having superior repair performance in wound repair experiments. Overall, the multifunctional polysaccharide hydrogels fabricated in this study are ideal for wound repair.


Assuntos
Casca de Ovo , Hidrogéis , Polissacarídeos , Cicatrização , Cicatrização/efeitos dos fármacos , Animais , Hidrogéis/química , Hidrogéis/farmacologia , Casca de Ovo/química , Ratos , Polissacarídeos/química , Polissacarídeos/farmacologia , Quitosana/química , Quitosana/farmacologia , Pós , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Ratos Sprague-Dawley
9.
Int J Biol Macromol ; 279(Pt 4): 135388, 2024 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-39255892

RESUMO

This study investigates the efficacy of a novel tissue-engineered scaffold for nerve repair and functional reconstruction following injury. Utilizing stable jet electrospinning, we fabricated aligned ultrafine fibers from dopamine and poly(L-lactic acid) (PLLA), further developing a biomimetic, oriented, and electroactive scaffold comprising poly(pyrrole) (PPy), polydopamine (PDA), and PLLA through dual in situ polymerizations. The scaffold demonstrated enhanced cell adhesion and reactive oxygen species (ROS) scavenging capabilities and promoted the differentiation of mesenchymal stem cells (MSCs) into Schwann-like cells, essential for nerve regeneration. In vivo assessments revealed significant peripheral nerve regeneration in 10 mm sciatic nerve defects in rats, with observations made 12 weeks post-transplantation. This included facilitated myelination and increased muscle density on the injured side, leading to improved motor function recovery. Our results suggest that the aligned PPy/PDA/PLLA fibrous scaffold offers a promising approach for promoting the differentiation of MSCs into Schwann-like cells conducive to nerve regeneration and represents a significant advancement in nerve repair technologies. This study provides a foundational basis for future research into tissue-engineered solutions for nerve damage, potentially impacting clinical strategies for nerve reconstruction.

10.
ACS Appl Mater Interfaces ; 15(35): 41385-41402, 2023 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-37606339

RESUMO

Effective repair and functional recovery of large peripheral nerve deficits are urgent clinical needs. A biofunctional electroactive scaffold typically acts as a "bridge" for the repair of large nerve defects. In this study, we constructed a biomimetic piezoelectric and conductive aligned polypyrrole (PPy)/polydopamine (PDA)/poly-l-lactic acid (PLLA) electrospun fibrous scaffold to improve the hydrophilicity and cellular compatibility of PLLA and restore the weakened piezoelectric effect of PDA, which is beneficial in promoting Schwann cell differentiation and dorsal root ganglion neuronal extension and alignment. The aligned PPy/PDA/PLLA fibrous scaffold bridged the sciatic nerve of Sprague-Dawley rats with a 10 mm deficit, prevented autotomy, and promoted nerve regeneration and functional recovery, thereby activating the calcium and AMP-activated protein kinase signaling pathways. Therefore, electroactive fibrous scaffolds exhibit great potential for neural tissue regeneration.


Assuntos
Polímeros , Pirróis , Ratos , Animais , Ratos Sprague-Dawley , Regeneração Nervosa , Nervo Isquiático
11.
Colloids Surf B Biointerfaces ; 228: 113416, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37348269

RESUMO

Development of a controlled delivery ultrafine fibrous system with two bioactive molecules is required to stimulate tendon healing in different phase. In this study, we used emulsion stable jet electrospinning to fabricate aligned poly(L-lactic acid) (PLLA) based ultrafine fibers with two small bioactive molecules of L-Arginine (Arg) and low molecular weight hyaluronic acid (HA). The results demonstrated that the aligned Arg/HA/PLLA microfibrous scaffold showed core-shell structure and allowed sequential release of Arg and HA due to their different electric charge. The scaffold also showed enhanced hydrophilicity, cell migration, spread and proliferation. Using an Achilles tendon repair model in rats, we demonstrated that this novel fibrous scaffold can prevent adhesion and promote tendon regeneration. Additionally, two p53 and ER-α-mediated signalling pathways were described as the probable main path of synergistic effects of the novel scaffold on tendon generation. Thus, this study may provide an important strategy for developing biofunctional and biomimetic tendon scaffolds.


Assuntos
Engenharia Tecidual , Alicerces Teciduais , Ratos , Animais , Engenharia Tecidual/métodos , Alicerces Teciduais/química , Tendões , Cicatrização , Poliésteres/química , Movimento Celular , Proliferação de Células
12.
Adv Sci (Weinh) ; 10(28): e2302519, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37612810

RESUMO

The development of self-healing conductive hydrogels is critical in electroactive nerve tissue engineering. Typical conductive materials such as polypyrrole (PPy) are commonly used to fabricate artificial nerve conduits. Moreover, the field of tissue engineering has advanced toward the use of products such as hyaluronic acid (HA) hydrogels. Although HA-modified PPy films are prepared for various biological applications, the cell-matrix interaction mechanisms remain poorly understood; furthermore, there are no reports on HA-modified PPy-injectable self-healing hydrogels for peripheral nerve repair. Therefore, in this study, a self-healing electroconductive hydrogel (HASPy) from HA, cystamine (Cys), and pyrrole-1-propionic acid (Py-COOH), with injectability, biodegradability, biocompatibility, and nerve-regenerative capacity is constructed. The hydrogel directly targets interleukin 17 receptor A (IL-17RA) and promotes the expression of genes and proteins relevant to Schwann cell myelination mainly by activating the interleukin 17 (IL-17) signaling pathway. The hydrogel is injected directly into the rat sciatic nerve-crush injury sites to investigate its capacity for nerve regeneration in vivo and is found to promote functional recovery and remyelination. This study may help in understanding the mechanism of cell-matrix interactions and provide new insights into the potential use of HASPy hydrogel as an advanced scaffold for neural regeneration.

13.
Biomacromolecules ; 13(12): 3917-25, 2012 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-23131188

RESUMO

In tissue engineering research, there has recently been considerable interest in using electrospun biomimetic nanofibers of hybrids, in particular, from natural and synthetic polymers for engineering different tissues. However, phase separation between a pair of much dissimilar polymers might give rise to detrimental influences on both the electrospinning process and the resultant fiber performance. A representative natural-synthetic hybrid of gelatin (GT) and polycaprolactone (PCL) (50:50) was employed to study the phase separation behavior in electrospinning of the GT/PCL composite fibers. Using trifluoroethanol (TFE) as the cosolvent of the two polymers, observation of visible sedimentation and flocculation from dynamic light scattering analysis of the GT/PCL/TFE mixture both showed that phase separation does occur in just a few hours. This consequently led to gradually deteriorated fiber morphologies (e.g., splash, fiber bonding, and varied fiber size) over time during electrospinning GT/PCL. Quantitative analysis also indicated that the ratio of GT to PCL in the resultant GT/PCL fibers was altered over time. To address the phase separation related issues, a tiny amount (<0.3%) of acetic acid was introduced to improve the miscibility, which enabled the originally turbid solution to become clear immediately and to be single-phase stable for more than 1 week. Nanofibers thus obtained also appeared to be thinner, smooth, and homogeneous with enhanced performance in wettability and mechanical properties. Given the versatility and widely uses of the electrospun GT/PCL and other similar natural-synthetic hybrid systems in constructing tissue-engineered scaffolds, this work may offer a facile and effective approach to achieve finer and compositionally homogeneous hybrid nanofibers for effective applications.


Assuntos
Ácido Acético/metabolismo , Gelatina/química , Nanofibras/química , Poliésteres/química , Varredura Diferencial de Calorimetria/métodos , Fluoresceína-5-Isotiocianato/metabolismo , Engenharia Tecidual/métodos , Alicerces Teciduais/química , Trifluoretanol/metabolismo , Difração de Raios X/métodos
14.
Nanotechnology ; 23(48): 485102, 2012 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-23128604

RESUMO

Engaging functional biomaterial scaffolds to regulate stem cell differentiation has drawn a great deal of attention in the tissue engineering and regenerative medicine community. In this study, biomimetic composite nanofibrous scaffolds of hydroxyapatite/chitosan (HAp/CTS) were prepared to investigate their capacity for inducing murine mesenchymal stem cells (mMSCs) to differentiate into the osteogenic lineage, in the absence and presence of an osteogenic supplementation (i.e., ascorbic acid, ß-glycerol phosphate, and dexamethasone), respectively. Using electrospun chitosan (CTS) nanofibrous scaffolds as the control, cell morphology, growth, specific osteogenic genes expression, and quantified proteins secretion on the HAp/CTS scaffolds were sequentially examined and assessed. It appeared that the HAp/CTS scaffolds supported better attachment and proliferation of the mMSCs. Most noteworthy was that in the absence of the osteogenic supplementation, expression of osteogenic genes including collagen I (Col I), runt-related transcription factor 2 (Runx2), alkaline phosphatase (ALP), and osteocalcin (OCN) were significantly upregulated in mMSCs cultured on the HAp/CTS nanofibrous scaffolds. Also increased secretion of the osteogenesis protein markers of alkaline phosphatase and collagen confirmed that the HAp/CTS nanofibrous scaffold markedly promoted the osteogenic commitment in the mMSCs. Moreover, the presence of osteogenic supplementation proved an enhanced efficacy of mMSC osteogenesis on the HAp/CTS nanofibrous scaffolds. Collectively, this study demonstrated that the biomimetic nanofibrous HAp/CTS scaffolds could support and enhance the adhesion, proliferation, and particularly osteogenic differentiation of the mMSCs. It also substantiated the potential of using biomimetic nanofibrous scaffolds of HAp/CTS for functional bone repair and regeneration applications.


Assuntos
Quitosana/química , Durapatita/química , Células-Tronco Mesenquimais/citologia , Nanofibras/química , Osteogênese , Alicerces Teciduais/química , Fosfatase Alcalina/metabolismo , Animais , Materiais Biomiméticos/química , Materiais Biomiméticos/metabolismo , Diferenciação Celular , Linhagem Celular , Proliferação de Células , Quitosana/metabolismo , Durapatita/metabolismo , Células-Tronco Mesenquimais/metabolismo , Camundongos , Nanofibras/ultraestrutura , Engenharia Tecidual
15.
Int J Biol Macromol ; 201: 338-350, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-35032490

RESUMO

The development of a new multi-functional poly(L)-lactide (PLLA) nanofibrous scaffold with excellent antibacterial and reactive oxygen species (ROS) scavenging capability is quite important in tissue engineering. In this study, polydopamine (PDA)/PLLA nanofibers were prepared by combining electrospinning and post in-situ polymerization. The post in-situ polymerization of PDA on the PLLA nanofiber enable PDA uniformly distribute on PLLA nanofiber surface. PDA/PLLA nanofibrous composites also achieved stronger mechanical strength, hydrophilicity, good oxidation resistance and enhanced near-infrared photothermal effect. The near-infrared photothermal effect from PDA made the PDA/PLLA a good antibacterial material. The in vitro ROS scavenging ability of the PDA made PDA/PLLA be beneficial to damaged tissue repair. These results indicate that PDA/PLLA nanofibrous scaffold can be used as a tissue engineering scaffold material with versatile biomedical applications.


Assuntos
Nanofibras , Antibacterianos/farmacologia , Indóis , Poliésteres , Polímeros , Espécies Reativas de Oxigênio , Engenharia Tecidual/métodos , Alicerces Teciduais
16.
Int J Biol Macromol ; 222(Pt B): 1948-1962, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36202331

RESUMO

Poor wound healing is a very common clinical problem, so far there is no completely satisfactory treatment. Electropsun nanofibrous wound dressings may provide an ideal structure to improve wound healing. Therefore, development of nanofibrous wound dressings with rapid hemostasis, antibacterial and tissue regenerative multi-functions has been a hotspot in the field of skin tissue engineering. In this work, polydopamine (PDA) and polypyrrole (PPy) were uniformly coated onto the surface of poly(l-lactide) (PLLA) nanofibers by in-situ polymerization, forming a novel PPy/PDA/PLLA three-layer core-shell structure. The homogeneously coated PPy and PDA two layers could significantly increase the hydrophilicity, conductivity, near-infrared photothermal antibacterial property, the speed of wound hemostasis, antioxidant capacity and reactive oxygen species (ROS) scavenging capacity, respectively. In addition, PPy/PDA/PLLA nanofibers showed good biocompatibility. Rat wound healing model confirmed that PPy/PDA/PLLA nanofibers could significantly accelerate wound repair in vivo. Thus, this novel nanofibrous wound dressing is a promising candidate for clinical wound healing.


Assuntos
Nanofibras , Ratos , Animais , Nanofibras/química , Polímeros/química , Pirróis/farmacologia , Cicatrização , Antibacterianos
17.
Mater Sci Eng C Mater Biol Appl ; 128: 112264, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34474823

RESUMO

Injectable self-healing hydrogels of natural polysaccharides that mimic the extracellular matrix to promote cellular growth are attractive materials for wound healing. Here, a novel hydrogel was fabricated based on carboxymethyl chitosan (CS) and aldehyde functionalized sodium alginate via Schiff base reaction. To enhance the hydrogel's properties, carboxymethyl-functionalized polymethyl methacrylate (PMAA) short nanofibers were obtained through sodium hydroxide-treated polymethyl methacrylate nanofibers, and added to a CS solution. Gelation time was determined for different hydrogels including 0-5 mg/mL PMAA short nanofibers. The nanofiber hydrogels were tested for their injectability and self-healing abilities and were demonstrated to be easily injectable with excellent self-healing abilities. Additionally, in vitro cytocompatibility experiments, good interaction between the cultured cells and hydrogels was seen. Further, the polysaccharide hydrogel containing short PMMA nanofibers significantly facilitated wound healing in rats compared with the polysaccharide hydrogel and control groups. Thus, the developed hydrogel has great potential for wound healing applications.


Assuntos
Quitosana , Nanofibras , Alginatos , Animais , Hidrogéis , Polissacarídeos , Ratos , Cicatrização
18.
Front Chem ; 9: 766078, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34858942

RESUMO

The excellent properties of nanomaterials have been confirmed in many fields, but their effects on plants are still unclear. In this study, different concentrations of bismuth vanadate (BV) were added to the growth medium to analyze the growth of seedlings, including taproots, lateral roots, leaf stomata, root activity, and superoxide anion O2 .- generation. Gene expression levels related to root growth were determined by quantitative PCR in Arabidopsis thaliana. The results showed that BV promoted the growth of taproots and the development of lateral roots, enhanced the length of the extension zone in roots, increased the number and size of leaf stomata and root activity, reduced the accumulation of ROS in seedlings, and changed the expression levels of genes related to polyamines or hormones. At the same time, we investigated the antibacterial activity of BV against a variety of common pathogens causing crop diseases. The results showed that BV could effectively inhibit the growth of Fusarium wilt of cotton and rice sheath blight. These results provide a new prospect for the development of nanomaterial-assisted plants, which is expected to become one of the ways to solve the problem of controlling and promoting the development of plants. At the same time, it also provides a reference for the study of the effect of BV on plants.

19.
Front Bioeng Biotechnol ; 9: 767641, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34976966

RESUMO

To regenerate bone tissues, we investigated the osteogenic differentiation of induced-pluripotent-stem-cell-derived mesenchymal stem cells (iPSC-MSCs) and bone regeneration capacities using N-acetyl cysteine (NAC)-loaded biomimetic nanofibers of hydroxyapatite/silk fibroin (HAp/SF). The addition of HAp and NAC decreased the diameters of the electrospun fibers and enhanced the mechanical properties of the silk scaffold. The release kinetic curve indicated that NAC was released from NAC/HAp/SF nanofibers in a biphasic pattern, with an initial burst release stage and a later sustained release stage. This pattern of release of NAC encapsulated on the NAC/HAp/SF scaffolds prolonged the release of high concentrations of NAC, thereby largely affecting the osteogenic differentiation of iPSC-MSCs and bone regeneration. Thus, a new silk electrospun scaffold was developed. HAp was used as a separate nanocarrier for recharging the NAC concentration, which demonstrated the promising potential for the use of NAC/HAp/SF for bone tissue engineering.

20.
Int J Biol Macromol ; 170: 248-260, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33359806

RESUMO

Functional tendon tissue engineering depends on harnessing the biochemical and biophysical cues of the native tendon extracellular matrix. In this study, we fabricated highly-aligned poly(L-lactic acid) (PLLA) fibers with surfaces decorated by two of the crucial tendon ECM components, type 1 collagen (COL1) and chondroitin sulfate (CS), through a coaxial stable jet electrospinning approach. Effects of the biomimetic COL1-CS (shell)/PLLA (core) fibers on the tenogenic differentiation of human mesenchymal stem cells (hMSCs) in vitro were investigated. Higher rates of cell spreading and proliferation are observed on the aligned COL1-CS/PLLA fibers compared to that on the plain PLLA fibers. Expression of the tendon-associated genes scleraxis (SCX) and COL1 as well as protein tenomodulin (TNMD) are significantly increased. Introduction of mechanical stimulation gives rise to synergistic effect on tenogenic differentiation of hMSCs. Higher expression of TGF-ß2, TGFßR-II, and Smad3 by the cells on the COL1-CS/PLLA fiber substrates are observed, which indicates that COL1-CS/PLLA ultrafine fibers dictate the hMSC tenogenic differentiation through activating the TGF-ß signaling pathway. Animal study in rat Achilles tendon repair model corroborated the promoting role of COL1-CS/PLLA in regenerating a tendon-like tissue. Thus, our highly aligned biomimicking fibers may serve as an efficient scaffolding system for functional tendon regeneration.


Assuntos
Sulfatos de Condroitina/farmacologia , Colágeno/farmacologia , Engenharia Tecidual/métodos , Adulto , Animais , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sulfatos de Condroitina/metabolismo , Colágeno/metabolismo , Colágeno Tipo I/metabolismo , Matriz Extracelular , Feminino , Humanos , Células-Tronco Mesenquimais/citologia , Ratos , Ratos Sprague-Dawley , Regeneração/efeitos dos fármacos , Tendões/citologia , Tendões/fisiologia , Alicerces Teciduais/química
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