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Biodegradable Polycaprolactone Fibers with Silica Aerogel and Nanosilver Particles Produce a Coagulation Effect. Polymers (Basel) 2023; 15:polym15092022. [PMID: 37177170 PMCID: PMC10180577 DOI: 10.3390/polym15092022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 11/08/2022] [Accepted: 04/18/2023] [Indexed: 05/15/2023] Open
Abstract
Poly-ε-caprolactone (PCL) is a biodegradable aliphatic polyester that can be used in the field of biomaterials. Electrospinning is the name given to the process of producing micro and nanoscale fibers using electrostatically charged polymeric solutions under certain conditions. Almost all synthetic and naturally occurring polymers can undergo electrospinning using suitable solvents or mixtures prepared in certain proportions. In this study, silica aerogels were obtained by the sol-gel method. PCL-silica aerogel fibers were synthesized by adding 0.5, 1, 2, and 4% ratios in the PCL solution. Blood contact analysis was performed on the produced fibers with UV-VIS. According to the results obtained, 0.5, 1, 2, and 4% nano-silver were added to the fiber-containing 4% aerogel. Then, SEM-EDS and FTIR analyses were performed on all fibers produced. Antimicrobial tests were performed on fibers containing nano-silver. As a result, high-performance blood coagulation fibers were developed using PCL with aerogel, and an antimicrobial effect was achieved with nano-silver particles. It is thought that the designed surface will be preferred in wound dressing and biomaterial in tissue engineering, as it provides a high amount of cell adhesion with a small amount of blood and contains antimicrobial properties.
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Endothelial Cell Behavior and Nitric Oxide Production on a-C:H:SiOx-Coated Ti-6Al-4V Substrate. Int J Mol Sci 2023; 24:ijms24076675. [PMID: 37047649 PMCID: PMC10095527 DOI: 10.3390/ijms24076675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 03/31/2023] [Accepted: 04/02/2023] [Indexed: 04/07/2023] Open
Abstract
This paper focuses on the surface modification of the Ti-6Al-4V alloy substrate via a-C:H:SiOx coating deposition. Research results concern the a-C:H:SiOx coating structure, investigated using transmission electron microscopy and in vitro endothelization to study the coating. Based on the analysis of the atomic radial distribution function, a model is proposed for the atomic short-range order structure of the a-C:H:SiOx coating, and chemical bonds (C–O, C–C, Si–C, Si–O, and Si–Si) are identified. It is shown that the a-C:H:SiOx coating does not possess prolonged cytotoxicity in relation to EA.hy926 endothelial cells. In vitro investigations showed that the adhesion, cell number, and nitric oxide production by EA.hy926 endothelial cells on the a-C:H:SiOx-coated Ti-6Al-4V substrate are significantly lower than those on the uncoated surface. The findings suggest that the a-C:H:SiOx coating can reduce the risk of endothelial cell hyperproliferation on implants and medical devices, including mechanical prosthetic heart valves, endovascular stents, and mechanical circulatory support devices.
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Effect of surface modification on physical and cellular properties of PCL thin film. Colloids Surf B Biointerfaces 2021; 200:111582. [PMID: 33493944 DOI: 10.1016/j.colsurfb.2021.111582] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 12/26/2020] [Accepted: 01/13/2021] [Indexed: 02/07/2023]
Abstract
Lack of suitable surface functional groups is one of the main limitations related to the cell attachment of Polycaprolactone (PCL). The aim of this research was to surface modify the PCL film using gelatin coating, via a simple physical entrapment process. In this regard, after preparation of PCL films using casting, they were immersed in each gelatin solutions. Consequently, chemical crosslinking using glutaraldehyde was performed to improve the stability of the PCL-gelatin film. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), Scanning electron microscope (SEM), contact angle measurement, strip tensile test, Dimethylthiazol-diphenyltetrazolium bromide (MTT) assay and Cell seeding were used to evaluate the quality of the coating layer, the thickness of PCL-gelatin film, the surface wettability, their mechanical properties, Cell viability and Cell attachment and proliferation respectively. Results showed that the amount of entrapped gelatin enhanced with increasing acetone in the gelatin solution. Surface modification led to a two-fold increment of mechanical strength, about 50% increase in elastic modulus, 54% in elongation and up to 11% increment in cell viability. Moreover, wettability and cell attachment of PCL film significantly enhanced, after gelatin modification. In conclusion, the simple and cost effective modification of PCL using gelatin entrapment could provide significant mechanical and biological properties making it a promising approach for development of three-dimensional scaffolds for bone tissue engineering.
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Unravelling the Immunotoxicity of Polycaprolactone Nanoparticles-Effects of Polymer Molecular Weight, Hydrolysis, and Blends. Chem Res Toxicol 2020; 33:2819-2833. [PMID: 33050694 DOI: 10.1021/acs.chemrestox.0c00208] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Poly-ε-caprolactone (PCL) is a biodegradable polyester that has FDA and CE approval as a medical device. Nonetheless, the lack of toxicity exhibited by the polymer cannot be extrapolated to its nanomaterial conformation. Despite PCL-based NPs being widely studied in the biomedical field for their advantages as controlled drug delivery systems, little data describe PCL NPs' toxicity, particularly immunotoxicity. This work assessed different PCL-based delivery systems intended for protein delivery regarding their immunotoxicity and hemocompatibility. Two different molecular weight PCL polymers were used, as well as blends with chitosan and glucan. Results showed that the presence of NaOH during the production of PCL2 NPs and PCL2/glucan NPs induced PCL alkali hydrolysis, generating more reactive groups (carboxyl and hydroxyl) that contributed to an increased toxicity of the NPs (higher reduction in peripheral blood mononuclear cell viability and lower hemocompatibility). PCL2/glucan NPs showed an anti-inflammatory activity characterized by the inhibition of LPS stimulated nitric oxide (NO) and TNF-α. In conclusion, generalizations among different PCL NP delivery systems must be avoided, and immunotoxicity assessments should be performed in the early stage of product development to increase the clinical success of the nanomedicine.
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Bioengineering a pre-vascularized pouch for subsequent islet transplantation using VEGF-loaded polylactide capsules. Biomater Sci 2020; 8:631-647. [PMID: 31729495 DOI: 10.1039/c9bm01280j] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The effectiveness of cell transplantation can be improved by optimization of the transplantation site. For some types of cells that form highly oxygen-demanding tissue, e.g., pancreatic islets, a successful engraftment depends on immediate and sufficient blood supply. This critical point can be avoided when cells are transplanted into a bioengineered pre-vascularized cavity which can be formed using a polymer scaffold. In our study, we tested surface-modified poly(lactide-co-caprolactone) (PLCL) capsular scaffolds containing the pro-angiogenic factor VEGF. After each modification step (i.e., amination and heparinization), the surface properties and morphology of scaffolds were characterized by ATR-FTIR and XPS spectroscopy, and by SEM and AFM. All modifications preserved the gross capsule morphology and maintained the open pore structure. Optimized aminolysis conditions decreased the Mw of PLCL only up to 10% while generating a sufficient number of NH2 groups required for the covalent immobilization of heparin. The heparin layer served as a VEGF reservoir with an in vitro VEGF release for at least four weeks. In vivo studies revealed that to obtain highly vascularized PLCL capsules (a) the optimal VEGF dose for the capsule was 50 μg and (b) the implantation time was four weeks when implanted into the greater omentum of Lewis rats; dense fibrous tissue accompanied by vessels completely infiltrated the scaffold and created sparse granulation tissue within the internal cavity of the capsule. The prepared pre-vascularized pouch enabled the islet graft survival and functioning for at least 50 days after islet transplantation. The proposed construct can be used to create a reliable pre-vascularized pouch for cell transplantation.
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A multicompartment vascular implant of electrospun wintergreen oil/ polycaprolactone fibers coated with poly(ethylene oxide). Biomed J 2020; 44:589-597. [PMID: 32389823 PMCID: PMC8640569 DOI: 10.1016/j.bj.2020.04.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 02/25/2020] [Accepted: 04/27/2020] [Indexed: 11/28/2022] Open
Abstract
Background The aim of the present study was to fabricate double layered scaffolds of electrospun polycaprolactone (PCL) and poly(ethylene oxide) (PEO). The electrospun PCL fibers were functionalized with wintergreen oil (WO) as a novel approach to prevent vascular grafts failure due to thrombosis by adjusting biomaterial–blood interactions. Methods PCL tubular scaffolds were prepared by electrospinning approach and coated with PEO as a hydrophilic polymer. The single and double layered scaffolds were characterized in terms of their morphological, chemical properties -as well as-hemocompatibility assays (i.e. prothrombin time, hemolysis percentage and platelets adhesion). Moreover, the antioxidant potential of WO-PCL samples were measured by 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) free radical assay. Results The results demonstrated that incorporation of WO during the electrospinning process decreased the PCL fiber diameter. In addition, the prothrombine time assay shows that WO could be used to lower the electrospun PCL fiber tendency to induce blood clotting. Moreover, SEM observations of platelets adhesion of both single and double layered PCL/PEO scaffolds fiber shows an increase of platelets number, compared with the scaffolds containing WO. Conclusions The antioxidant potential and blood compatibility measurements of WO-PCL/PEO samples highlight the approach made so far as an ideal synthetic small size vascular grafts to overcome autogenous grafts shortages and drawbacks.
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Poly (vinylpyrrolidone)‑iodine engineered poly (ε-caprolactone) nanofibers as potential wound dressing materials. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2020; 110:110731. [PMID: 32204042 DOI: 10.1016/j.msec.2020.110731] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 02/04/2020] [Accepted: 02/05/2020] [Indexed: 02/08/2023]
Abstract
Facilitating the process of wound healing and effective treatment of wounds remains a serious challenge in healthcare. Wound dressing materials play a major role in the protection of wounds and in accelerating the natural healing process. In the present study, novel core/shell (c/s) nanofibrous mats of poly(vinyl pyrrolidone)‑iodine (PVPI) and polycaprolactone (PCL) were fabricated using a co-axial electrospinning process followed by their surface modification with poly-l-lysine. The developed nanofibrous mats were extensively characterized for their physicochemical properties using various analytical techniques. The core/shell structure of the PVP-I/PCL nanofibers was confirmed using TEM analysis. The PVP-I release studies showed an initial burst phase followed by a sustained release pattern of PVP-I over a period of 30 days. The developed nanofibers exhibited higher BSA and fibrinogen adsorption as compared to pristine PCL. Cytotoxicity studies using MTT assay demonstrated that the PVP-I/PCL (c/s) nanofibers were cytocompatible at optimized PVP-I concentration (3 wt%). The PCL-poly-l-lysine and PVP-I/PCL-poly-l-lysine nanofibers exhibited higher cell viability (24.2% and 21.4% higher at day 7) when compared to uncoated PCL and PVP-I/PCL nanofibers. The PVP-I/PCL nanofibers showed excellent antimicrobial activity against both Gram-positive (S. aureus) and Gram-negative (E. coli) bacteria. The inflammatory response of Mouse RAW 264.7 macrophage cells towards the nanofibers was studied using RT-PCR. It revealed that the pro-inflammatory cytokines (TNF-α and IL-1β) were significantly upregulated on PCL nanofibers, while their expression was comparatively lower on poly-l-lysine coated PCL or PVP-I/PCL(c/s) nanofibers. Overall, the study highlights the ability of poly-l-lysine coated PVP-I/PCL (c/s) nanofibers as potential wound dressing materials effectively facilitating the early stage wound healing and repair process by virtue of their selective modulation of inflammation, cell adhesion and antimicrobial properties.
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Clopidogrel eluting electrospun polyurethane/polyethylene glycol thromboresistant, hemocompatible nanofibrous scaffolds. J Biomater Appl 2019; 33:1327-1347. [DOI: 10.1177/0885328219832984] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Biomaterials used as blood-contacting material must be hemocompatible and exhibit lower thrombotic potential while maintaining hemostasis and angiogenesis. With the aim of developing thromboresistant, hemocompatible nanofibrous scaffolds, polyurethane/polyethylene glycol scaffolds incorporated with 1, 5, and 10 wt% Clopidogrel were fabricated and evaluated for their physiochemical properties, biocompatibility, hemocompatibility, and antithrombotic potential. The results of physicochemical characterization revealed the fabrication of nanometer-sized scaffolds with smooth surfaces. The incorporation of both polyethylene glycol and Clopidogrel to polyurethane enhanced the hydrophilicity and water uptake potential of polyurethane/polyethylene glycol/Clopidogrel scaffolds. The dynamic mechanical analysis revealed the enhancement in mechanical strength of the polyurethane/polyethylene glycol scaffolds on incorporation of Clopidogrel. The polyurethane/polyethylene glycol/Clopidogrel scaffolds showed a tri-phasic drug release pattern. The results of hemocompatibility assessment demonstrated the excellent blood compatibility of the polyurethane/polyethylene glycol/Clopidogrel scaffolds, with the developed scaffolds exhibiting lower hemolysis, increased albumin and plasma protein adsorption while reduction in fibrinogen adsorption. Further, the platelet adhesion was highly suppressed and significant increase in coagulation period was observed for Clopidogrel incorporated scaffolds. The results of cell adhesion and cell viability substantiate the biocompatibility of the developed nanofibrous scaffolds with the HUVEC cell viability on polyurethane/polyethylene glycol, polyurethane/polyethylene glycol/Clopidogrel-1, 5, and 10% at day 7 found to be 12.35, 13.36, 14.85, and 4.18% higher as compared to polyurethane scaffolds, and the NIH/3T3 cell viability found to be 35.27, 70.82, 36.60, and 7.95% higher as compared to polyurethane scaffolds, respectively. Altogether the results of the study advocate the incorporation of Clopidogrel to the polyurethane/polyethylene glycol blend in order to fabricate scaffolds with appropriate antithrombotic property, hemocompatibility, and cell proliferation capacity and thus, might be successfully used as antithrombotic material for biomedical application.
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A review on biocompatibility nature of hydrogels with 3D printing techniques, tissue engineering application and its future prospective. Biodes Manuf 2018. [DOI: 10.1007/s42242-018-0029-7] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Electrospun poly(ε-caprolactone) matrices containing silver sulfadiazine complexed with β-cyclodextrin as a new pharmaceutical dosage form to wound healing: preliminary physicochemical and biological evaluation. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2018; 29:67. [PMID: 29748753 DOI: 10.1007/s10856-018-6079-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2017] [Accepted: 04/21/2018] [Indexed: 06/08/2023]
Abstract
Cooperation between researchers in the areas of medical, pharmaceutical and materials science has facilitated the development of pharmaceutical dosage forms that elicit therapeutic effects and protective action with a single product. In addition to optimizing pharmacologic action, such dosage forms provide greater patient comfort and increase success and treatment compliance. In the present work, we prepared semipermeable bioactive electrospun fibers for use as wound dressings containing silver sulfadiazine complexed with β-cyclodextrin in a poly(Ɛ-caprolactone) nanofiber matrix aiming to reduce the direct contact between silver and skin and to modulate the drug release. Wound dressings were prepared by electrospinning, and were subjected to ATR-FT-IR and TG/DTG assays to evaluate drug stability. The hydrophilicity of the fibrous nanostructure in water and PBS buffer was studied by goniometry. Electrospun fibers permeability and swelling capacity were assessed, and a dissolution test was performed. In vitro biological tests were realized to investigate the biological compatibility and antimicrobial activity. We obtained flexible matrices that were each approximately 1.0 g in weight. The electrospun fibers were shown to be semipermeable, with water vapor transmission and swelling indexes compatible with the proposed objective. The hydrophilicity was moderate. Matrices containing pure drug modulated drug release adequately during 24 h but presented a high hemolytic index. Complexation promoted a decrease in the hemolytic index and in the drug release but did not negatively impact antimicrobial activity. The drug was released predominantly by diffusion. These results indicate that electrospun PCL matrices containing β-cyclodextrin/silver sulfadiazine inclusion complexes are a promising pharmaceutical dosage form for wound healing.
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Biocompatibility of hydrogel-based scaffolds for tissue engineering applications. Biotechnol Adv 2017; 35:530-544. [DOI: 10.1016/j.biotechadv.2017.05.006] [Citation(s) in RCA: 407] [Impact Index Per Article: 58.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Revised: 05/08/2017] [Accepted: 05/22/2017] [Indexed: 12/15/2022]
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Physical Characterization and Platelet Interactions under Shear Flows of a Novel Thermoset Polyisobutylene-based Co-polymer. ACS APPLIED MATERIALS & INTERFACES 2015; 7:22058-22066. [PMID: 26398588 PMCID: PMC4608843 DOI: 10.1021/acsami.5b07254] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Over the years, several polymers have been developed for use in prosthetic heart valves as alternatives to xenografts. However, most of these materials are beset with a variety of issues, including low material strength, biodegradation, high dynamic creep, calcification, and poor hemocompatibility. We studied the mechanical, surface, and flow-mediated thrombogenic response of poly(styrene-coblock-4-vinylbenzocyclobutene)-polyisobutylene-poly(styrene-coblock-4-vinylbenzocylcobutene) (xSIBS), a thermoset version of the thermoplastic elastomeric polyolefin poly(styrene-block-isobutylene-block-styrene) (SIBS), which has been shown to be resistant to in vivo hydrolysis, oxidation, and enzymolysis. Uniaxial tensile testing yielded an ultimate tensile strength of 35 MPa, 24.5 times greater than that of SIBS. Surface analysis yielded a mean contact angle of 82.05° and surface roughness of 144 nm, which was greater than for poly(ε-caprolactone) (PCL) and poly(methyl methacrylate) (PMMA). However, the change in platelet activation state, a predictor of thrombogenicity, was not significantly different from PCL and PMMA after fluid exposure to 1 dyn/cm(2) and 20 dyn/cm(2). In addition, the number of adherent platelets after 10 dyn/cm(2) flow exposure was on the same order of magnitude as PCL and PMMA. The mechanical strength and low thrombogenicity of xSIBS therefore suggest it as a viable polymeric substrate for fabrication of prosthetic heart valves and other cardiovascular devices.
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Smooth Muscle Cell Alignment and Phenotype Control by Melt Spun Polycaprolactone Fibers for Seeding of Tissue Engineered Blood Vessels. Int J Biomater 2015; 2015:434876. [PMID: 26413093 PMCID: PMC4568037 DOI: 10.1155/2015/434876] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2015] [Revised: 08/04/2015] [Accepted: 08/11/2015] [Indexed: 11/24/2022] Open
Abstract
A method has been developed to induce and retain a contractile phenotype for vascular smooth muscle cells, as the first step towards the development of a biomimetic blood vessel construct with minimal compliance mismatch. Melt spun PCL fibers were deposited on a mandrel to form aligned fibers of 10 μm in diameter. The fibers were bonded into aligned arrangement through dip coating in chitosan solution. This formed a surface of parallel grooves, 10 μm deep by 10 μm across, presenting a surface layer of chitosan to promote cell surface interactions. The aligned fiber surface was used to culture cells present in the vascular wall, in particular fibroblasts and smooth muscle cells. This topography induced “surface guidance” over the orientation of the cells, which adopted an elongated spindle-like morphology, whereas cells on the unpatterned control surface did not show such orientation, assuming more rhomboid shapes. The preservation of VSMC contractile phenotype on the aligned scaffold was demonstrated by the retention of α-SMA expression after several days of culture. The effect was assessed on a prototype vascular graft prosthesis fabricated from polylactide caprolactone; VSMCs aligned longitudinally along a fiberless tube, whereas, for the aligned fiber coated tubes, the VSMCs aligned in the required circumferential orientation.
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From flab to fab: transforming surgical waste into an effective bioactive coating material. Adv Healthc Mater 2015; 4:613-20. [PMID: 25424903 DOI: 10.1002/adhm.201400514] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Revised: 11/07/2014] [Indexed: 12/31/2022]
Abstract
Cellular events are regulated by the interaction between integrin receptors in the cell membrane and the extracellular matrix (ECM). Hence, ECM, as a material, can potentially play an instructive role in cell-material interactions. Currently, adipose tissue in the form of lipoaspirate is often discarded. Here, it is demonstrated how our chemical-free decellularization method could be used to obtain ECM from human lipoaspirate waste material. These investigations show that the main biological components are retained in the lipoaspirate-derived ECM (LpECM) material and that this LpECM material could subsequently be used as a coating material to confer bioactivity to an otherwise inert biodegradable material (i.e., polycaprolactone). Overall, lipoaspirate material, a complex blend of endogenous proteins, is effectively used a bioactive coating material. This work is an important stepping-stone towards the development of biohybrid scaffolds that contain cellular benefits without requiring the use of additional biologics based on commonly discarded lipoaspirate material.
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Abstract
Polymers have found widespread applications in cardiology, in particular in coronary vascular intervention as stent platforms (scaffolds) and coating matrices for drug-eluting stents. Apart from permanent polymers, current research is focussing on biodegradable polymers. Since they degrade once their function is fulfilled, their use might contribute to the reduction of adverse events like in-stent restenosis, late stent-thrombosis, and hypersensitivity reactions. After reviewing current literature concerning polymers used for cardiovascular applications, this review deals with parameters of tissue and blood cell functions which should be considered to evaluate biocompatibility of stent polymers in order to enhance physiological appropriate properties. The properties of the substrate on which vascular cells are placed can have a large impact on cell morphology, differentiation, motility, and fate. Finally, methods to assess these parameters under physiological conditions will be summarized.
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Functionalizable hydrogel microparticles of tunable size and stiffness for soft-tissue filler applications. Acta Biomater 2014; 10:2563-73. [PMID: 24561708 DOI: 10.1016/j.actbio.2014.02.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 01/17/2014] [Accepted: 02/12/2014] [Indexed: 01/26/2023]
Abstract
Particle size, stiffness and surface functionality are important in determining the injection site, safety and efficacy of injectable soft-tissue fillers. Methods to produce soft injectable biomaterials with controlled particle characteristics are therefore desirable. Here we report a method based on suspension photopolymerization and semi-interpenetrating network (semi-IPN) to synthesize soft, functionalizable, spherical hydrogel microparticles (MP) of independently tunable size and stiffness. MP were prepared using acrylated forms of polyethylene glycol (PEG), gelatin and hyaluronic acid. Semi-IPN MP of PEG-diacrylate and PEG were used to study the effect of process parameters on particle characteristics. The process parameters were systematically varied to produce MP with size ranging from 115 to 515μm and stiffness ranging from 190 to 1600Pa. In vitro studies showed that the MP thus prepared were cytocompatible. The ratio and identity of the polymers used to make the semi-IPN MP were varied to control their stiffness and to introduce amine groups for potential functionalization. Slow-release polymeric particles loaded with Rhodamine or dexamethasone were incorporated in the MP as a proof-of-principle of drug incorporation and release from the MP. This work has implications in preparing injectable biomaterials of natural or synthetic polymers for applications as soft-tissue fillers.
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Zwitterionic hyperbranched polyester functionalized cardiovascular stent and its biocompatibility. J Colloid Interface Sci 2014; 420:88-96. [DOI: 10.1016/j.jcis.2014.01.016] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Revised: 01/10/2014] [Accepted: 01/10/2014] [Indexed: 12/26/2022]
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Surface modifying oligomers used to functionalize polymeric surfaces: Consideration of blood contact applications. J Appl Polym Sci 2014. [DOI: 10.1002/app.40328] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Investigation of the long-term patency of a transmural heparinized polycaprolactone and poly(D,L-lactic/glycolic acid) scaffold. J Surg Res 2013; 187:394-402. [PMID: 24280687 DOI: 10.1016/j.jss.2013.10.049] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Revised: 10/11/2013] [Accepted: 10/24/2013] [Indexed: 10/26/2022]
Abstract
BACKGROUND The transmural biodegradable polycaprolactone/poly(D,L-lactic/glycolic acid) (PCL/PLGA) scaffold is a promising modality for diffuse coronary atherosclerosis cases that are not suitable for bypass grafting. The purpose of this study was to evaluate the long-term performance of the PCL/PLGA scaffold in vivo in the setting of polymer and heparin degradation. MATERIALS AND METHODS After mechanical drilling through the ventricular wall was performed in the whole ventricular wall, two scaffolds were implanted into the ventricular wall. Animals were grouped into the single drilling group (SD group), the blank scaffold group (BS group), and the heparinized scaffold group (HS group) and were allowed to survived for 6 mo. Next, the patency and integrity of the scaffolds were evaluated by echocardiography and 3D-DOCTOR software. Endothelium coverage of the lumen was evaluated by scanning electron microscopy. Neovessels and collagen fiber within the scaffolds were identified by histologic staining. Metabolite production of prostacyclin (PGI2) and thromboxane A2 (TXA2) in the plasma was measured by an enzyme-linked immunosorbent assay. The expression levels of PGI2 synthase and cyclooxygenase 2 (COX-2) involved in PGI2 production and COX-1 involved in TXA2 production were measured by Western blot analysis. RESULTS The heparinized scaffolds were patent for up to 6 mo and the lumen was covered with confluent endothelial cells. Histologic staining revealed collagen fiber remodeling and reconstruction of the neovascular network immediately surrounding the lumen. The expression of PGI2 synthase and COX-2 in the HS group was significantly higher compared with the SD and BS groups (P < 0.01). The expression of COX-1 was similar in the three groups (P > 0.05). Consistent with synthetase expression, a PGI2 metabolite (6-keto-PGF1a) also showed a significant increase in the HS group relative to the SD and BS groups (P = 0.021 and P = 0.015, respectively). Concomitantly, as a PGI2 antagonist, the TXA2 metabolite (TXB2) did not exhibit a significant difference among the three groups (P = 0.17). CONCLUSIONS Despite polymer and heparin degradation, the scaffold could continuously maintain the structural integrity and lumen patency for up to 6 mo by reinforcement of host collagen fiber and the balance of PGI2/TXA2.
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Antibiofilm properties of silver and gold incorporated PU, PCLm, PC and PMMA nanocomposites under two shear conditions. PLoS One 2013; 8:e63311. [PMID: 23675476 PMCID: PMC3652832 DOI: 10.1371/journal.pone.0063311] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2012] [Accepted: 04/01/2013] [Indexed: 11/26/2022] Open
Abstract
Silver and gold nanoparticles (of average size ∼20-27 nm) were incorporated in PU (Polyurethane), PCLm (Polycaprolactam), PC (polycarbonate) and PMMA (Polymethylmethaacrylate) by swelling and casting methods under ambient conditions. In the latter method the nanoparticle would be present not only on the surface, but also inside the polymer. These nanoparticles were prepared initially by using a cosolvent, THF. PU and PCLm were dissolved and swollen with THF. PC and PMMA were dissolved in CHCl₃ and here the cosolvent, THF, acted as an intermediate between water and CHCl₃. FTIR indicated that the interaction between the polymer and the nanoparticle was through the functional group in the polymer. The formation of E.coli biofilm on these nanocomposites under low (in a Drip flow biofilm reactor) and high shear (in a Shaker) conditions indicated that the biofilm growth was higher (twice) in the former than in the latter (ratio of shear force = 15). A positive correlation between the contact angle (of the virgin surface) and the number of colonies, carbohydrate and protein attached on it were observed. Ag nanocomposites exhibited better antibiofilm properties than Au. Bacterial attachment was highest on PC and least on PU nanocomposite. Casting method appeared to be better than swelling method in reducing the attachment (by a factor of 2). Composites reduced growth of organisms by six orders of magnitude, and protein and carbohydrate by 2-5 times. This study indicates that these nanocomposites may be suitable for implant applications.
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Vascular tissue engineering of small-diameter blood vessels: reviewing the electrospinning approach. J Tissue Eng Regen Med 2013; 9:861-88. [DOI: 10.1002/term.1697] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Revised: 10/08/2012] [Accepted: 12/20/2012] [Indexed: 11/07/2022]
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Synthesis and Characterization of Hydrophilic High Glycolic Acid–Poly(dl-Lactic-co-Glycolic Acid)/ Polycaprolactam/Polyvinyl Alcohol Blends and Their Biomedical Application as a Ureteral Material. Ind Eng Chem Res 2012. [DOI: 10.1021/ie3022253] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Green Synthesis of Protein Stabilized Silver Nanoparticles Using Pseudomonas fluorescens, a Marine Bacterium, and Its Biomedical Applications When Coated on Polycaprolactam. Ind Eng Chem Res 2012. [DOI: 10.1021/ie2029392] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Immobilization of subtilisin on polycaprolactam for antimicrobial food packaging applications. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2011; 59:10869-10878. [PMID: 21910484 DOI: 10.1021/jf201124v] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Subtilisin was immobilized on polycaprolactam and used for food packaging applications to reduce the transference of microorganisms from the packaging material to the packaged food material. The optimized conditions for subtilisin immobilization was as follows: pH, 8; temperature, 4 °C; glutaraldehyde, 0.5%; incubation time, 25 h; and subtilisin concentration, 600 μL. The formation of -CH═N- at 1576 cm(-1) in the Fourier transform infrared (FTIR) spectrum confirmed the immobilization. Subtilisin-immobilized polycaprolactam (SIP) exhibited the highest residual activity of 106.67 ± 4.41% and 104.67 ± 0.88% at 40 °C and pH 8 and retained residual activity of 94% at the end of 56 days when compared to 21.33 ± 4.10% in the case of free subtilisin. SIP significantly (p < 0.05) lowered the colony forming units (CFU), dry weight, and protein and carbohydrate contents in bacterial and fungal biofilm. Practical application of the SIP on ham steaks at 4 and 20 °C showed a 2-3 times reduction of Staphylococcus aureus as well as Escherichia coli cells in the range of p < 0.05.
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Physicochemical characterisation and biological evaluation of polyvinylpyrrolidone-iodine engineered polyurethane (Tecoflex(®)). JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2011; 22:1231-1246. [PMID: 21437640 DOI: 10.1007/s10856-011-4285-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2010] [Accepted: 03/08/2011] [Indexed: 05/30/2023]
Abstract
Bacterial adhesion and encrustation are the known causes for obstruction or blockage of urethral catheters and ureteral stents, which often hinders their effective use within the urinary tract. In this in vitro study, polyvinylpyrrolidone-iodine (PVP-I) complex modified polyurethane (Tecoflex(®)) systems were created by physically entrapping the modifying species during the reversible swelling of the polymer surface region. The presence of the PVP-I molecules on this surfaces were verified by ATR-FTIR, AFM and SEM-EDAX analysis, while wettability of the films was investigated by water contact angle measurements. The modified surfaces were investigated for its suitability as a urinary tract biomaterial by comparing its lubricity and ability to resist bacterial adherence and encrustation with that of base polyurethane. The PVP-I modified polyurethane showed a nanopatterned surface topography and was highly hydrophilic and more lubricious than control polyurethane. Adherence of both the gram positive Staphylococcus aureus (by 86%; **P < 0.01) and gram-negative Pseudomonas aeruginosa (by 80%; *P < 0.05) was significantly reduced on the modified surfaces. The deposition of struvite and hydroxyapatite the major components of urinary tract encrustations were significantly less on PVP-I modified polyurethane as compared to base polyurethane, especially reduction in hydroxyapatite encrustation was particularly marked. These results demonstrated that the PVP-I entrapment process can be applied on polyurethane in order to reduce/lower complications associated with bacterial adhesion and deposition of encrustation on polyurethanes.
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