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1.
Biomater Adv ; 154: 213628, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37769531

RESUMO

Subcutaneous transplantation aims to enhance the growth and functionality of transplanted cells for therapeutic outcomes in tissue engineering. However, the limited subcutaneous vascular network poses a challenge. Conventional methods involve co-transplantation with endothelial cells or angiogenic scaffold implantation, but they have drawbacks like tissue inflammation, compromised endothelial cell functionality, and the risk of repeated scaffold transplantation. Effective techniques are needed to overcome these challenges. This study explores the potential of G/O-NGD, a gel-in-oil nanogel dispersion, as a transdermal carrier of proliferative factors to promote angiogenesis in subcutaneous graft beds before cell transplantation. We observed robust subcutaneous angiogenesis by delivering varying amounts of bFGF using the G/O-NGD emulsion. Quantitative analysis of several parameters confirmed the efficacy of this method for building a subcutaneous vascular network. G/O-NGD is a biodegradable material that facilitates localized transdermal delivery of bFGF while maintaining its activity. The findings of this study have significant implications in both medical and industrial fields.


Assuntos
Células Endoteliais , Neovascularização Fisiológica , Nanogéis , Fenômenos Fisiológicos Cardiovasculares
2.
Biomedicines ; 11(6)2023 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-37371687

RESUMO

Oxygen is one of the essential requirements for cell survival, retention, and proliferation. The field of regenerative medicine and tissue engineering (TE) has realized considerable achievements for the regeneration of tissues. However, tissue regeneration still lacks the full functionality of solid organ implantations; limited cell survival and retention due to oxidative stress and hypoxia in the deeper parts of tissues remains a perpetual challenge. Especially prior to neovascularization, hypoxia is a major limiting factor, since oxygen delivery becomes crucial for cell survival throughout the tissue-engineered construct. Oxygen diffusion is generally limited in the range 100-200 µm of the thickness of a scaffold, and the cells located beyond this distance face oxygen deprivation, which ultimately leads to hypoxia. Furthermore, before achieving functional anastomosis, implanted tissues will be depleted of oxygen, resulting in hypoxia (<5% dissolved oxygen) followed by anoxic (<0.5% dissolved oxygen) microenvironments. Different types of approaches have been adopted to establish a sustained oxygen supply both in vitro and in vivo. In this review, we have summarized the recent developments in oxygen-generating and/or releasing biomaterials for enhancing cell survival in vitro, as well as for promoting soft and hard tissue repair, including skin, heart, nerve, pancreas, muscle, and bone tissues in vivo. In addition, redox-scavenging biomaterials and oxygenated scaffolds have also been highlighted. The surveyed results have shown significant promise in oxygen-producing biomaterials and oxygen carriers for enhancing cell functionality for regenerative medicine and TE applications. Taken together, this review provides a detailed overview of newer approaches and technologies for oxygen production, as well as their applications for bio-related disciplines.

3.
ACS Omega ; 8(10): 9239-9249, 2023 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-36936322

RESUMO

Ultraviolet (UV) radiation from the sun or artificial sources is one of the primary causes of skin damage, including sunburns, tanning, erythema, and skin cancer. Among the three different types of UV rays, UVB rays have a medium wavelength that can penetrate the epidermal layer of the skin, resulting in sunburn, suntan, blistering, and melanoma in case of chronic exposure. This study aimed to evaluate the preventive and therapeutic effects of a gel-in-oil nanogel dispersion (G/O-NGD) as a transdermal delivery biomolecular carrier for skin damage caused by UVB light. The efficacy of this carrier against UVB-induced skin damage was investigated in vivo by delivering different growth factors (GFs) encapsulated in a G/O-NGD. Artificial UVB light was used to induce skin damage in nude mice, followed by the transdermal application of five GF [vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), transforming growth factor (TGF)-1, and insulin-like growth factor (IGF)-α]-immobilized G/O-NGD. Among these GFs, VEGF and bFGF promoted angiogenesis, while EGF, TGF-1, and IGF-α promoted the repair and regeneration of damaged cells. The results showed that G/O-NGD was superior to heparin-immobilized G/O-NGD in reducing UVB-induced skin damage, such as erythema, epidermal water reduction, inflammation, and dermis thickening. In addition, G/O-NGD could prevent and treat abnormal follicle proliferation caused by UVB rays and exhibited potential to repair lipid glands. Overall, our results demonstrate the potential of G/O-NGDs for the treatment of UVB-induced skin damage.

4.
Colloids Surf B Biointerfaces ; 223: 113140, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36669437

RESUMO

Skin regeneration is hindered by poor vascularization, prolonged inflammation, and excessive scar tissue formation, which necessitate newer strategies to simultaneously induce blood vessel regeneration, resolve inflammation, and induce host cell recruitment. Concurrent deployment of multiple biological cues to realize synergistic reparative effects may be an enticing avenue for wound healing. Herein, we simultaneously deployed SDF (stromal cell-derived factor)- 1α, VEGF (vascular endothelial growth factor)-binding peptide (BP), and GLP (glucagon like peptide)- 1 analog, liraglutide (LG) in core/shell poly(L-lactide-co-glycolide)/gelatin fibers to harness their synergistic effects for skin repair in healthy as well as diabetic wound models in rats. Microscopic techniques, such as SEM and TEM revealed fibrous and core/shell type morphology of membranes. Boyden chamber assay and scratch-wound assay displayed significant migration of HUVECs (human umbilical vein endothelial cells) in SDF-1α containing fibers. Subcutaneous implantation of membranes revealed higher cellular infiltration in SDF-1α loaded fibers, especially, those which were co-loaded with LG or BP. Implantation of membranes in an excisional wound model in healthy rats further showed significant and rapid wound closure in dual cues loaded groups as compared to control or single cue loaded groups. Similarly, the implantation of dressings in type 2 diabetes rat model revealed fast healing, skin appendages regeneration, and blood vessel regeneration in dual cues loaded fibers (SDF-1α/LG, SDF-1α/BP). Taken together, core/shell type fibers containing bioactive peptides significantly promoted wound repair in healthy as well as diabetic wound models in rats.


Assuntos
Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Ratos , Humanos , Animais , Gelatina/farmacologia , Sinais (Psicologia) , Fator A de Crescimento do Endotélio Vascular/metabolismo , Quimiocina CXCL12/farmacologia , Cicatrização , Células Endoteliais da Veia Umbilical Humana/metabolismo , Inflamação
5.
Transl Vis Sci Technol ; 11(5): 16, 2022 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-35576213

RESUMO

Purpose: The aim of this study was to develop a nanogel emulsion as a minimally invasive, safe, and effective treatment alternative for posterior ocular diseases. Methods: A gel-in-water (G/W) nanoemulsion was developed by ultrasonication using beeswax as an organogelator. Different physicochemical properties were evaluated along with particle size analysis by dynamic light scattering. In vitro biocompatibility of G/W nanoemulsion using rat hepatocytes and human umbilical vein endothelial cells (HUVECs) and in vivo corneal permeability as eye drops were investigated. Results: The nanogel emulsion was monodispersed with a polydispersity index and particle diameter of approximately 0.2 and 200 nm, respectively. The zeta potential value of -8.1 mV suggested enhanced stability and improved retinal permeability of nanoparticles. The prepared nanoemulsion was found to be biocompatible with hepatocytes and HUVECs in vitro. Moreover, in vivo study demonstrated high permeability of G/W nanoemulsion to the retinal layer with no ocular irritation. Conclusions: G/W nanoemulsions have the potential for topical drug delivery in the posterior eye segment with maximum therapeutic efficacy. Translational Relevance: Organogel nanodispersion is a new concept to deliver hydrophobic drugs to the posterior segment of eyes as a novel drug delivery system.


Assuntos
Células Endoteliais , Água , Animais , Sistemas de Liberação de Medicamentos , Emulsões/química , Nanogéis , Ratos
6.
Gels ; 8(5)2022 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-35621610

RESUMO

Researchers have long awaited the technology to develop an in vitro kidney model. Here, we establish a rapid fabricating technique for kidney-like tissues (cysts) using a combination of an organ-derived extracellular matrix (ECM) gel format culture system and a renal stem cell line (CHK-Q cells). CHK-Q cells, which are spontaneously immortalized from the renal stem cells of the Chinese hamster, formed renal cyst-like structures in a type-I collagen gel sandwich culture on day 1 of culture. The cysts fused together and expanded while maintaining three-dimensional structures. The expression of genes related to kidney development and maturation was increased compared with that in a traditional monolayer. Under the kidney-derived ECM (K-ECM) gel format culture system, cyst formation and maturation were induced rapidly. Gene expressions involved in cell polarities, especially for important material transporters (typical markers Slc5a1 and Kcnj1), were restored. K-ECM composition was an important trigger for CHK-Q cells to promote kidney-like tissue formation and maturation. We have established a renal cyst model which rapidly expressed mature kidney features via the combination of K-ECM gel format culture system and CHK-Q cells.

7.
Surg Today ; 52(7): 1109-1114, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35018512

RESUMO

PURPOSE: At present, ≥ 20% of patients experience clinically relevant postoperative pancreatic fistula (POPF) after distal pancreatectomy (DP). METHODS: We developed a new bioabsorbable pancreatic clip (BioPaC) made of polycaprolactone that does not crush the pancreatic parenchyma during occlusion of the pancreatic stump. We confirmed the efficacy of this BioPac in a porcine DP model and compared it to a linear stapling device (Reinforce®). RESULTS: Pigs were killed at 1 month after DP. In the BioPaC group, all swine (n = 3) survived well without POPF. In the Reinforce® group (n = 2), one pig died early at postoperative day 7 with Grade C POPF (amylase 43 700 U/l), and the other survived until 1 month at scarification with biochemical leakage of POPF (amylase 3 725 U/l). Pathologically, the main pancreatic duct and pancreatic parenchyma were well closed by BioPaC. CONCLUSION: The newly developed BioPaC is effective in a porcine DP model.


Assuntos
Implantes Absorvíveis , Pancreatectomia , Amilases , Animais , Humanos , Fístula Pancreática/etiologia , Fístula Pancreática/prevenção & controle , Complicações Pós-Operatórias , Estudos Retrospectivos , Fatores de Risco , Instrumentos Cirúrgicos , Suínos
8.
J Biosci Bioeng ; 133(2): 174-180, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34789413

RESUMO

Organogels are semi-solid systems that can gel organic liquids at low concentrations. The use of organogels in drug delivery has grown rapidly in the last decade owing to their fibrous microstructure and suitability for different routes of administration. The current study is characterized by nanogel dispersion (NGD) development based on emulsion technology. The efficiency of this organogel based NGD as a carrier for anticancer drugs was assessed both in vitro and in vivo. 12-Hydroxystearic acid formed an organogel with lipiodol and encapsulated the anticancer drug paclitaxel. The gel-in-water (G/W) nanodispersion was prepared via ultrasonication and stabilized by a nonionic surfactant. The results showed that the organogel enabled sustained drug release from G/W nanodispersion over time, along with enhanced cellular uptake. The prepared G/W nanodispersion was found to be biocompatible with mouse hepatocytes and fibroblast cells in vitro, whereas paclitaxel-loaded G/W nanodispersion showed cytotoxicity (p <0.05) against lung cancer (A549) cell lines. Similarly, intravenous administration of paclitaxel-loaded G/W nanodispersion exerts an anticancer effect against lung cancer in vivo, with a significant decrease in tumor volume (p <0.05). Therefore, the proposed G/W nanodispersion could be a promising carrier for chemotherapy agents with sustained drug release and better therapeutic outcomes against cancer.


Assuntos
Antineoplásicos , Nanopartículas , Administração Intravenosa , Animais , Portadores de Fármacos , Sistemas de Liberação de Medicamentos , Emulsões , Géis , Camundongos , Água
9.
Adv Exp Med Biol ; 1345: 241-252, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34582027

RESUMO

The nervous system is an ensemble of organs that transmit and process external information and are responsible for the adaption to the external environment and homeostasis control of the internal environment. The nervous system of vertebrates is divided into the central nervous system (CNS) and peripheral nervous system (PNS) due to its structural features. The CNS, which includes the brain and the spinal cord, processes information from external stimuli and assembles orders suitable for these stimuli. The CNS then sends signals to control other organs/tissues. On the other hand, the PNS connects the CNS to other organs/tissues and functions as a signal pathway. Therefore, the decline and loss of various functions due to injuries of the nervous system cause an impaired quality of life (QOL) and eventually the termination of life activities. Here, we report mainly on decellularized neural tissue and its application as a substrate for the regeneration of the nervous system.


Assuntos
Tecido Nervoso , Qualidade de Vida , Animais , Sistema Nervoso Central , Regeneração Nervosa , Sistema Nervoso Periférico , Medula Espinal
10.
Mater Sci Eng C Mater Biol Appl ; 124: 112076, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33947568

RESUMO

The effective delivery of anti-cancer drugs with minimal side effects and better therapeutic efficacy has remained an active area of research for many decades. Organogels have gained attention in recent years as potential drug delivery systems due to their high bioavailability, no first-pass metabolism and rapid action. Considering this, in the current study an organogel based nanoemulsion was developed aiming to effectively deliver hydrophobic drugs via encapsulation within in situ gellable organogel droplets, termed as gel-in-water (G/W) nanoemulsion. G/W nanoemulsion was prepared using a combination of lipiodol and organogelator 12-hydroxystearic acid (12-HSA) as inner gel phase; dispersed in water by ultrasonication and stabilized with polyoxyethylene hydrogenated castor oil (HCO-60) as a surfactant. The prepared nanoemulsion showed high drug loading efficiency (≈97%) with a mean diameter of 206 nm. Lower polydispersity index (PdI) value (≈0.1) suggests monodispersed nature of G/W nanoemulsion in the continuous phase. G/W nanoemulsion was found stable over six months in terms of particle size, zeta potential and pH at different storage temperatures. There was no cytotoxic effect of prepared G/W nanoemulsion on primary hepatocytes in vitro. In contrast, paclitaxel-loaded G/W showed a significant decrease in melanoma cell growth (*p < 0.05) both in vitro and in vivo. Our results support the hypothesis that organogel based nanoemulsions can be a promising drug delivery system.


Assuntos
Nanopartículas , Água , Sistemas de Liberação de Medicamentos , Emulsões , Tamanho da Partícula , Tensoativos
11.
J Biosci Bioeng ; 132(1): 95-101, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33883072

RESUMO

Growth factors (GFs) are indispensable in regenerative medicine because of their high effectiveness. However, as GFs degenerate easily, the development of a suitable carrier with improved stability for GFs is necessary. In this study, we developed a gel-in-oil (G/O) emulsion technology for the transdermal delivery of growth factors. Nanogel particles prepared with heparin-immobilized gelatin that can bind growth factors were dispersed in isopropyl myristate. The particle size of the G/O emulsion could be controlled by changing the surfactant concentration, volume ratio of the water phase to the oil phase, and gelatin concentration. In vitro skin penetration studies showed better penetration through the stratum corneum of fluorescent proteins containing G/O emulsions than of the aqueous solution of GF. Similarly, an in vivo study showed an angiogenesis-inducing effect after transdermal application of GF-immobilized G/O emulsion. Angiogenesis in mice was confirmed owing to both an increased blood vessel network and higher hemoglobin content in the blood. Therefore, the G/O emulsion could be a promising carrier for GFs with better stability and can effectively deliver GFs at the target site.


Assuntos
Portadores de Fármacos/química , Peptídeos e Proteínas de Sinalização Intercelular/administração & dosagem , Peptídeos e Proteínas de Sinalização Intercelular/química , Óleos/química , Administração Cutânea , Animais , Emulsões , Gelatina/química , Géis , Camundongos , Miristatos/química , Tamanho da Partícula , Água/química
12.
J Biosci Bioeng ; 132(1): 71-80, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33895082

RESUMO

Cryopreservation is important for enabling long-term cell preservation. However, physical damage due to ice crystal formation and membrane permeation by dimethyl sulfoxide (DMSO) severely affects cryopreserved cell viability. To ensure cell survival and functional maintenance after cryopreservation, it is important to protect the cell membrane, the most vulnerable cell component, from freeze-thaw damage. This study aimed to create a glycolipid derivative having a positive interaction with the cell membrane and cytoprotective effects. As a result, we synthesized a novel trehalose derivative, oleyl-trehalose (Oleyl-Treh), composed of trehalose and oleyl groups. Its use led to increased viable cell counts when used with DMSO in a non-cytotoxic concentration range (1.6 nM-16 µM). Oleyl-Treh significantly improved viability and liver-specific functions of hepatocytes after cryopreservation, including albumin secretion, ethoxyresorufin-O-deethylase activity (an indicator of cytochrome P450 family 1 subfamily A member 1 activity), and ammonia metabolism. Oleyl-Treh could localize trehalose to the cell membrane; furthermore, the oleyl group affected cell membrane fluidity and exerted cryoprotective effects. This novel cryoprotective agent, which shows a positive interaction with the cell membrane, provides a unique approach toward cell protection during cryopreservation.


Assuntos
Membrana Celular/efeitos dos fármacos , Criopreservação/métodos , Crioprotetores/química , Crioprotetores/farmacologia , Glicolipídeos/química , Trealose/química , Trealose/farmacologia , Animais , Membrana Celular/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Hepatócitos/citologia , Hepatócitos/efeitos dos fármacos , Humanos
13.
J Biosci Bioeng ; 131(1): 107-113, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32948422

RESUMO

Liver transplantation plays an important role in the medical field. To improve the quality of a donor liver, there is a need to establish a preservation system to prevent damage and maintain liver function. In response to this demand, machine perfusion (MP) has been proposed as a new liver preservation method instead of the conventional static cold storage. There is controversy about the optimal MP temperature of the donor liver. Since the oxygen consumption of the liver differs depending on the temperature, construction of a system that satisfies the oxygen demand of the liver is crucial for optimizing the preservation temperature. In this study, an MP system, which satisfies the oxygen demand of liver at each temperature, was constructed using an index of oxygen supply; the overall volumetric oxygen transfer coefficient, the amount of oxygen retention of perfusate and oxygen saturation. Both subnormothermic MP (SNMP, 20-25 °C) and normothermic MP (NMP, 37 °C) could maintain liver viability at a high level (94%). However, lactate metabolism of the liver during NMP was more active than that during SNMP. Furthermore, the ammonia metabolism of liver after NMP was superior to that after SNMP. Hence, NMP, which maintains the metabolic activity of the liver, is more suitable for preservation of the donor liver than SNMP, which suppresses the metabolic activity. In summary, normothermia is the optimal temperature for liver preservation, and we succeeded in constructing an NMP system that could suppress liver damage and maintain function.


Assuntos
Fígado/fisiologia , Oxigênio/metabolismo , Perfusão/métodos , Temperatura , Humanos , Fígado/metabolismo , Transplante de Fígado , Doadores Vivos
14.
Int J Biol Macromol ; 151: 186-192, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32070734

RESUMO

Endothelization of a tissue-engineered substrate is important for its application as an artificial vascular graft. Despite recent advancements in artificial graft fabrication, a graft of <5 mm is difficult to fabricate owing to insufficient endothelization that results in thrombosis after transplantation. We aimed to perform a co-culture of adipose-derived mesenchymal stem cells (MSCs) with human umbilical vein endothelial cells (HUVECs) on antithrombogenic polycaprolactone (PCL)/heparin-gelatin co-spun nanofibers to evaluate the role of co-culturing in promoting quick endothelization of vascular substrates without surface modification by growth factors or other ECM proteins that trigger the endothelization process. Using a co-axial electrospinning technique, we attempted to fabricate our scaffold balancing between mechanical properties and biocompatibility. Antithrombogenic characteristics were then imparted to the fabricated nanofiber substrate by grafting of heparin. Finally, we performed a co-culture of MSCs and HUVECs on the fabricated co-spun nanofiber substrate to obtain proper endothelization of our material under the in-vitro culture. Staining for CD-31 at seven days of culture revealed enhanced CD-31 expression under the co-culture condition; actin staining revealed healthy cobblestone HUVEC morphology, suggesting that MSCs can aid in proper endothelization. Hence, we conclude that co-culture is effective for quick endothelization of vascular substrates.


Assuntos
Gelatina , Heparina , Células Endoteliais da Veia Umbilical Humana/metabolismo , Células-Tronco Mesenquimais/citologia , Nanofibras , Poliésteres , Alicerces Teciduais/química , Diferenciação Celular , Técnicas de Cocultura , Citoesqueleto/química , Citoesqueleto/metabolismo , Endotélio , Imunofluorescência , Gelatina/química , Heparina/química , Humanos , Nanofibras/química , Nanofibras/ultraestrutura , Poliésteres/química , Engenharia Tecidual
15.
Regen Ther ; 15: 173-179, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33426216

RESUMO

INTRODUCTION: Cells have various applications in biomedical research. Cryopreservation is a cell-preservation technique that provides cells for such applications. After cryopreservation, sensitive cells, such as primary hepatocytes, suffer from low viability due to the physical damage caused by ice crystals, highlighting the need for better methods of cryopreservation to improve cell viability. Given the importance of effectively suppressing ice crystal formation to protect cellular structure, trehalose has attracted attention as cryoprotectant based on its ability to inhibit ice crystal formation; however, trehalose induces osmotic stress. Therefore, to establish a cell-cryopreservation technique, it is necessary to provide an optimal balance between the protective and damaging effects of trehalose. METHODS: In this study, we evaluated the effects of osmotic stress and ice crystal formation on the viability and function of primary rat hepatocytes at wide range of trehalose concentration. RESULTS: There was no osmotic stress at very low concentrations (2.6 µM) of trehalose, and 2.6 µM trehalose drives the formation of finer ice crystals, which are less damaging to the cell membrane. Furthermore, we found that the number of viable hepatocytes after cryopreservation were 70% higher under the 2.6 µM trehalose-supplemented conditions than under the dimethyl sulfoxide-supplemented conditions. Moreover, non-cryopreserved cells and cells cryopreserved with trehalose showed comparable intracellular dehydrogenase activity. CONCLUSIONS: We showed that trehalose at very low concentrations (2.6 µM) improved dramatically viability and liver function of hepatocyte after cryopreservation.

16.
Regen Ther ; 15: 236-242, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33426224

RESUMO

INTRODUCTION: Growth factors are crucial bioactive molecules in vitro and in vivo. Among them, basic fibroblast growth factor (bFGF) has been used widely for various applications such as cell culture and regenerative medicine. However, bFGF has extremely poor stability in aqueous solution; thus, it is difficult to maintain its high local concentration. Heparin-conjugated materials have been studied recently as promising scaffold-immobilizing growth factors for biological and medical applications. The previous studies have focused on the local concentration maintenance and sustained release of the growth factors from the scaffold. METHODS: In this paper, we focused on the biological stability of bFGF immobilized on the heparin-conjugated collagen (hep-col) scaffold. The stability of the immobilized bFGF was quantitatively evaluated at physiological temperature (37 °C) using cell culture and ELISA. RESULTS: The immobilized bFGF had twice higher stability than the bFGF solution. Furthermore, the hep-col scaffold was able to immobilize not only bFGF but also other growth factors (i.e., vascular endothelial growth factor and hepatocyte growth factor) at high efficiency. CONCLUSIONS: The hep-col scaffold can localize several kinds of growth factors as well as stabilize bFGF under physiological temperature and is a promising potent scaffold for regenerative medicine.

17.
J Biosci Bioeng ; 129(3): 354-362, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31601468

RESUMO

Aligned fibers have been used as a scaffold of nerve guidance conduit owing to their guiding function of neural cells for peripheral nerve regeneration. However, the recovery performance of nerve guidance conduits using aligned fibrous scaffold is insufficient, and further improvements in scaffold function is required for promoting regeneration. In this study, we developed aligned heparin-conjugated fibers and supplied a biological signal to neural cells by the growth factors immobilized through heparin. Results indicated that neural model cells (PC12 cells) were cultured well on the scaffold without inhibiting cell adhesion by heparin conjugation and exhibited more vigorous cell proliferation than in a heparin-free condition. The cells extended their neurites along the fiber direction. Furthermore, PC12 cells on the heparin-conjugated fibrous scaffold pre-exposed to a nerve growth factor solution sprouted more neurites compared to those of heparin-free condition. These results verified that our scaffold exhibited high biocompatibility to neural cells and could maintain an effective local concentration of growth factors on the scaffold surface. Therefore, aligned heparin-conjugated fibers are promising scaffolds of nerve guidance conduits for promoting peripheral nerve regeneration by the combinatorial effect of topological and biological signals.


Assuntos
Nanofibras , Fator de Crescimento Neural/farmacologia , Regeneração Nervosa/efeitos dos fármacos , Neurônios/citologia , Animais , Heparina/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Células PC12 , Ratos
18.
Regen Ther ; 11: 258-268, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31667205

RESUMO

The extracellular matrix (ECM) in a liver-specific extracellular matrix (L-ECM) scaffold facilitates hepatocyte viability and maintains hepatocyte functions in vitro. However, whether an intact composition of ECM is required for an efficient ECM-based substrate design remains to be clarified. In this study, two L-ECM hydrogels, namely L-ECM I and L-ECM II, were prepared by pepsin solubilization at 4 °C and 25 °C, respectively. The solubility at 4 °C was 50% whereas that at 25 °C was 95%, thus indicating well-preserved L-ECM. Analysis confirmed higher ECM protein components (especially collagen) in L-ECM II, along with denser fiber network and larger fiber diameter. L-ECM II gel exhibited high compression strength and suitable viscoelastic properties. Furthermore, hepatocytes in L-ECM II showed higher expression of liver-specific functions in 3D culture and wider spread while maintaining the cell-cell contacts in 2D culture. Therefore, an intact L-ECM is important to realize effective substrates for liver tissue engineering.

19.
Int J Pharm ; 567: 118495, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31276761

RESUMO

We developed a new oil-based delivery system for transdermal protein delivery, a gel-in-oil (G/O) nanosuspension, where gelatin-based hydrogel was coated with hydrophobic surfactants. The high entrapment efficiency of a model protein, phycocyanin (PC), into nano-sized gelatin hydrogel particles was achieved. Spectroscopic evaluation of PC suggested that the G/O nanosuspension could retain the functional form of PC in isopropyl myristate. In vitro skin permeation studies showed that the G/O nanosuspension facilitated the delivery of PC through the stratum corneum of Yucatan micropig skin.


Assuntos
Portadores de Fármacos/administração & dosagem , Gelatina/administração & dosagem , Hidrogéis/administração & dosagem , Miristatos/administração & dosagem , Nanopartículas/administração & dosagem , Ficocianina/administração & dosagem , Administração Cutânea , Animais , Feminino , Óleos/administração & dosagem , Tamanho da Partícula , Pele/metabolismo , Absorção Cutânea , Suínos , Porco Miniatura
20.
Gels ; 5(2)2019 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-31212711

RESUMO

Hydrogels and their medical applications in tissue engineering have been widely studied due to their three-dimensional network structure, biocompatibility, and cell adhesion. However, the development of an artificial bile duct to replace the recipient's tissue is still desired. Some challenges remain in the tissue engineering field, such as infection due to residual artifacts. In other words, at present, there are no established technologies for bile duct reconstruction as strength and biocompatibility problems. Therefore, this study investigated hydrogel as an artificial bile duct base material that can replace tissue without any risk of infectious diseases. First, an antibacterial agent (ABA), Finibax (an ABA used for the clinical treatment of biliary tract infection), was immobilized in gelatin using a crosslinking agent, and the antibacterial properties of the gel and its sustainability were tested. Furthermore, the immobilized amount and the improvement of the proliferation of the human umbilical vein endothelial cells (HUVECs) were cultured as the ABA-Gelatin hydrogel was introduced to prepare a 3D scaffold. Finally, we performed hematoxylin and eosin (H&E) staining after subcutaneous implantation in the rat. Overall, the ABA-Gelatin hydrogel was found to be viable for use in hydrogel applications for tissue engineering due to its good bactericidal ability, cell adhesion, and proliferation, as well as having no cytotoxicity to cells.

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