Tailoring the in vitro characteristics of poly(vinyl alcohol)-nanohydroxyapatite composite scaffolds for bone tissue engineering

2016 ◽  
Vol 36 (8) ◽  
pp. 771-784 ◽  
Author(s):  
Tejinder Kaur ◽  
Arunachalam Thirugnanam ◽  
Krishna Pramanik

Abstract Poly(vinyl alcohol) reinforced with nanohydroxyapatite (PVA-nHA) composite scaffolds were developed by varying the nHA (1%, 2%, 3%, 4%, and 5%, w/v) composition in the PVA matrix by solvent casting technique. The developed composite scaffolds were characterized using scanning electron microscopy (SEM), X-ray powder diffraction (XRD), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, and contact angle measurement. The stability of the composite scaffolds in physiological environment was evaluated by swelling and degradation studies. Further, these composite scaffolds were tested for in vitro bioactivity, hemolysis, biocompatibility, and mechanical strength. SEM micrographs showed a homogenous distribution of nHA (3%, w/v) in the PVA matrix. XRD and ATR-FTIR analysis confirmed no phase contamination and the existence of the chemical bond between PVA-nHA at approximately 2474 cm-1. PVA-nHA composite scaffolds with 3% (w/v) concentration of nHA showed nominal swelling and degradation behavior with good mechanical strength. The mechanical strength and degradation properties of the scaffold above 3% (w/v) of nHA was found to deteriorate, which is due to the agglomeration of nHA. The in vitro bioactivity and hemolysis studies showed improved apatite formation and hemocompatibility of the developed scaffolds. In vitro cell adhesion, proliferation, alkaline phosphatase activity, and Alizarin red S staining confirmed the biocompatibility of the composite scaffolds.

2018 ◽  
Vol 10 (1) ◽  
pp. 115 ◽  
Author(s):  
Napaphak Jaipakdee ◽  
Thaned Pongjanyakul ◽  
Ekapol Limpongsa

Objective: The objectives of this study were to prepare and characterize a buccal mucoadhesive patch using poly (vinyl alcohol) (PVA), poly (vinyl pyrrolidone) (PVP) as a mucoadhesive matrix, Eudragit S100 as a backing layer, and lidocaine HCl as a model drug.Methods: Lidocaine HCl buccal patches were prepared using double casting technique. Molecular interactions in the polymer matrices were studied using attenuated total reflectance-fourier transform infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC) and X-ray diffractometry. Mechanical and mucoadhesive properties were measured using texture analyzer. In vitro permeation of lidocaine HCl from the patch was conducted using Franz diffusion cell.Results: Both of the free and lidocaine HCl patches were smooth and transparent, with good flexibility and strength. ATR-FTIR, DSC and X-ray diffractometry studies confirmed the interaction of PVA and PVP. Mechanical properties of matrices containing 60% PVP were significantly lower than those containing 20% PVP (*P<0.05). Mucoadhesive properties had a tendency to decrease with the concentration of PVP in the patch. The patch containing 60% PVP had significantly lower muco-adhesiveness than those containing 20% PVP (*P<0.05). In vitro permeation revealed that the pattern of lidocaine HCl permeation started with an initial fast permeation, followed by a slower permeation rate. The initial permeation fluxes follow the zero-order model of which rate was not affected by the PVP concentrations in the PVA/PVP matrix.Conclusion: Mucoadhesive buccal patches fabricated with PVA/PVP were successfully prepared. Incorporation of PVP in PVA/PVP matrix affected the strength of polymeric matrix and mucoadhesive property of patches.


2005 ◽  
Vol 284-286 ◽  
pp. 469-472 ◽  
Author(s):  
Caihong You ◽  
Toshiki Miyazaki ◽  
Eiichi Ishida ◽  
Masahiro Ashizuka ◽  
Chikara Ohtsuki ◽  
...  

Organic polymers with ability of apatite formation in body environment are expected as novel bone substitutes having not only bone-bonding ability, i.e. bioactivity, but also mechanical performance analogous to natural bone. Several metal oxides have been found to be effective for the apatite deposition in body environment. In addition, release of calcium ions from the materials significantly enhances it. In this study, we attempted to synthesize bioactive organic-inorganic hybrids from Poly(vinyl alcohol) (PVA) by incorporation of various metal oxides and calcium salt. Silica and molybdenum oxides were selected as metal oxides. Ability of apatite formation on the hybrids was examined in vitro using simulated body fluid (SBF, Kokubo solution). Apatite deposition were observed to occur on the surfaces of PVA/silica and PVA/molybdenum oxide hybrids in SBF, when their compositions were appropriately controlled.


2006 ◽  
Vol 309-311 ◽  
pp. 1153-1156 ◽  
Author(s):  
Caihong You ◽  
Toshiki Miyazaki ◽  
Eiichi Ishida ◽  
Masahiro Ashizuka ◽  
Chikara Ohtsuki

Organic polymers with ability of apatite formation in body environment are expected as novel bone substitutes having not only bone-bonding ability, i.e. bioactivity, but also mechanical performance analogous to natural bone. Several metal oxides have been found to be effective for the apatite deposition in body environment. In addition, release of calcium ions from the materials significantly enhances it. In this study, we attempted to synthesize bioactive organic-inorganic hybrids from poly(vinyl alcohol) (PVA) by incorporation of titanium oxide or zirconium oxide as well as calcium salt. Ability of apatite formation on the hybrids was examined in vitro using simulated body fluid (SBF, Kokubo solution). Apatite deposition was observed to occur on the surfaces of PVA/titanium oxide hybrids in SBF, when their compositions were appropriately controlled.


Membranes ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 110
Author(s):  
Prakash B. Kalahal ◽  
Akshay S. Kulkarni ◽  
Ashok M. Sajjan ◽  
T. M. Yunus Khan ◽  
Irfan Anjum Badruddin ◽  
...  

Tetraethylorthosilicate (TEOS)-crosslinked poly(vinyl alcohol) (PVA) solution was prepared and treated with benzaldehyde 2 sulphonic sodium salt acid (B2SA) for sulfonation. Different contents of graphene were incorporated into B2SA-grafted PVA–TEOS hybrid membrane to improve the membrane stability, mechanical strength, and overall pervaporation performance of the membranes. Membranes were fabricated using the casting technique. Developed membranes were then analyzed for their physicochemical changes by means of Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron microscope (SEM), wide-angle X-ray diffraction (WAXD), thermogravimetric analysis (TGA), contact angle analysis (CA), and mechanical strength. The lower d-spacing value observed in WAXD was evidence for the decreased inter-chain distance between the polymer chains. DSC exhibited the enhanced thermal stability of the developed membranes compared to the plane PVA membrane with enhancement in Tg value (106 °C), which was well above the pervaporation experimental temperature. Incorporation of graphene induced higher mechanical strength to the fabricated membranes. Further, the membranes were tested for the pervaporation separation of bioethanol. All the membranes were stable throughout the pervaporation studies, with M-2 G showing the total permeation flux of 11.66 × 10−2 kg/(m2 h) at 30 °C.


2012 ◽  
Vol 85 (4) ◽  
pp. 547-558 ◽  
Author(s):  
Sa-Ad Riyajan ◽  
Nataphon Pheweaw

ABSTRACT Pressure-sensitive adhesives (PSAs), or self-adhesives, are used in many applications, including safety labels for power equipment, automotive interior trim assembly, and sound/vibration–damping films. The objective of this study was to develop a biodegradable skim rubber–based bioadhesive blended with poly (vinyl alcohol) (PVA), which has the advantage of being biodegradable and biocompatible to humans. PSAs were produced from saponified low-protein skim rubber (S-LPSR) alone using a hydrocarbon resin as a tackifier and blends of S-LPSR/PVA containing tackifier, via solution and emulsion, respectively. The influence of 2,6-di-t-butyl-4-methylphenol (BHT) and the hydrocarbon resin content in the adhesive formulation was studied. Various methods were used to evaluate the properties of the adhesives produced including scanning electron microscopy, differential scanning calorimetry, contact angle measurement, dynamic mechanical thermal analysis, and Fourier transform infrared spectroscopy. The optimal concentration of PVA for a good PSA was found to be 20 phr because of its emulsion form. The adhesion properties of a PSA containing 50–60 phr of hydrocarbon resin and 1% BHT displayed excellent tack and peel compared with other samples because there was no chain scission of the skim rubber and good compatibility and interaction between the S-LPSR/PVA blend and the hydrocarbon resin, which maximized the adhesion properties of the adhesive.


2021 ◽  
Vol 8 (8) ◽  
pp. 107
Author(s):  
Lilis Iskandar ◽  
Lucy DiSilvio ◽  
Jonathan Acheson ◽  
Sanjukta Deb

Despite considerable advances in biomaterials-based bone tissue engineering technologies, autografts remain the gold standard for rehabilitating critical-sized bone defects in the oral and maxillofacial (OMF) region. A majority of advanced synthetic bone substitutes (SBS’s) have not transcended the pre-clinical stage due to inferior clinical performance and translational barriers, which include low scalability, high cost, regulatory restrictions, limited advanced facilities and human resources. The aim of this study is to develop clinically viable alternatives to address the challenges of bone tissue regeneration in the OMF region by developing ‘dual network composites’ (DNC’s) of calcium metaphosphate (CMP)—poly(vinyl alcohol) (PVA)/alginate with osteogenic ions: calcium, zinc and strontium. To fabricate DNC’s, single network composites of PVA/CMP with 10% (w/v) gelatine particles as porogen were developed using two freeze–thawing cycles and subsequently interpenetrated by guluronate-dominant sodium alginate and chelated with calcium, zinc or strontium ions. Physicochemical, compressive, water uptake, thermal, morphological and in vitro biological properties of DNC’s were characterised. The results demonstrated elastic 3D porous scaffolds resembling a ‘spongy bone’ with fluid absorbing capacity, easily sculptable to fit anatomically complex bone defects, biocompatible and osteoconductive in vitro, thus yielding potentially clinically viable for SBS alternatives in OMF surgery.


Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2252
Author(s):  
Jae Eun Kim ◽  
Sangbae Park ◽  
Woong-Sup Lee ◽  
Jinsub Han ◽  
Jae Woon Lim ◽  
...  

The use of bone graft materials is required for the treatment of bone defects damaged beyond the critical defect; therefore, injectable calcium phosphate cement (CPC) is actively used after surgery. The application of various polymers to improve injectability, mechanical strength, and biological function of injection-type CPC is encouraged. We previously developed a chitosan–PEG conjugate (CS/PEG) by a sulfur (VI) fluoride exchange reaction, and the resulting chitosan derivative showed high solubility at a neutral pH. We have demonstrated the CPC incorporated with a poly (ethylene glycol) (PEG)-grafted chitosan (CS/PEG) and developed CS/PEG CPC. The characterization of CS/PEG CPC was conducted using Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The initial properties of CS/PEG CPCs, such as the pH, porosity, mechanical strength, zeta potential, and in vitro biocompatibility using the WST-1 assay, were also investigated. Moreover, osteocompatibility of CS/PEG CPCs was carried out via Alizarin Red S staining, immunocytochemistry, and Western blot analysis. CS/PEG CPC has enhanced mechanical strength compared to CPC, and the cohesion test also demonstrated in vivo stability. Furthermore, we determined whether CS/PEG CPC is a suitable candidate for promoting the osteogenic ability of Dental Pulp Stem Cells (DPSC). The elution of CS/PEG CPC entraps more calcium ion than CPC, as confirmed through the zeta potential test. Accordingly, the ion trapping effect of CS/PEG is considered to have played a role in promoting osteogenic differentiation of DPSCs. The results strongly suggested that CS/PEG could be used as suitable additives for improving osteogenic induction of bone substitute materials.


2019 ◽  
Vol 20 (20) ◽  
pp. 5126 ◽  
Author(s):  
Caterina Cristallini ◽  
Serena Danti ◽  
Bahareh Azimi ◽  
Veronika Tempesti ◽  
Claudio Ricci ◽  
...  

The objective of this study was the preparation and physico-chemical, mechanical, biological, and functional characterization of a multifunctional coating for an innovative, fully implantable device. The multifunctional coating was designed to have three fundamental properties: adhesion to device, close mechanical resemblance to human soft tissues, and control of the inflammatory response and tissue repair process. This aim was fulfilled by preparing a multilayered coating based on three components: a hydrophilic primer to allow device adhesion, a poly(vinyl alcohol) hydrogel layer to provide good mechanical compliance with the human tissue, and a layer of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) fibers. The use of biopolymer fibers offered the potential for a long-term interface able to modulate the release of an anti-inflammatory drug (dexamethasone), thus contrasting acute and chronic inflammation response following device implantation. Two copolymers, poly(vinyl acetate-acrylic acid) and poly(vinyl alcohol-acrylic acid), were synthetized and characterized using thermal analysis (DSC, TGA), Fourier transform infrared spectroscopy (FT-IR chemical imaging), in vitro cell viability, and an adhesion test. The resulting hydrogels were biocompatible, biostable, mechanically compatible with soft tissues, and able to incorporate and release the drug. Finally, the multifunctional coating showed a good adhesion to titanium substrate, no in vitro cytotoxicity, and a prolonged and controlled drug release.


Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 96
Author(s):  
John Jackson ◽  
Helen Burt ◽  
Dirk Lange ◽  
In Whang ◽  
Robin Evans ◽  
...  

The prompt treatment of burn wounds is essential but can be challenging in remote parts of Africa, where burns from open fires are a constant hazard for children and suitable medical care may be far away. Consequently, there is an unmet need for an economical burn wound dressing with a sustained antimicrobial activity that might be manufactured locally at low cost. This study describes and characterizes the novel preparation of a silver nitrate-loaded/poly(vinyl alcohol) (PVA) film. Using controlled heating cycles, films may be crosslinked with in situ silver nanoparticle production using only a low heat oven and little technical expertise. Our research demonstrated that heat-curing of PVA/silver nitrate films converted the silver to nanoparticles. These films swelled in water to form a robust, wound-compatible hydrogel which exhibited controlled release of the antibacterial silver nanoparticles. An optimal formulation was obtained using 5% (w/w) silver nitrate in PVA membrane films that had been heated at 140 °C for 90 min. Physical and chemical characterization of such films was complemented by in vitro studies that confirmed the effective antibacterial activity of the released silver nanoparticles against both gram positive and negative bacteria. Overall, these findings provide economical and simple methods to manufacture stable, hydrogel forming wound dressings that release antibiotic silver over prolonged periods suitable for emergency use in remote locations.


2021 ◽  
Vol 27 (2) ◽  
pp. 421-428
Author(s):  
Rudranarayan Kandi ◽  
Pulak Mohan Pandey ◽  
Misba Majood ◽  
Sujata Mohanty

Purpose This paper aims to discuss the successful fabrication of customized tubular scaffolds for tracheal tissue engineering with a novel route using solvent-based extrusion 3D printing. Design/methodology/approach The manufacturing approach involved extrusion of polymeric ink over a rotating predefined pattern to construct customized tubular structure of polycaprolactone (PCL) and polyurethane (PU). Dimensional deviation in thickness of scaffolds were calculated for various layer thicknesses of 3D printing. Physical and chemical properties of scaffolds were investigated by scanning electron microscope (SEM), contact angle measurement, Fourier Transform Infrared Spectroscopy (FTIR) and X-ray diffraction (XRD). Mechanical characterizations were performed, and the results were compared to the reported properties of human native trachea from previous reports. Additionally, in vitro cytotoxicity of the fabricated scaffolds was studied in terms of cell proliferation, cell adhesion and hemagglutination assay. Findings The developed fabrication route was flexible and accurate by printing customized tubular scaffolds of various scales. Physiochemical results showed good miscibility of PCL/PU blend, and decrease in crystalline nature of blend with the addition of PU. Preliminary mechanical assessments illustrated comparable mechanical properties with the native human trachea. Longitudinal compression test reported outstanding strength and flexibility to maintain an unobstructed lumen, necessary for the patency. Furthermore, the scaffolds were found to be biocompatible to promote cell adhesion and proliferation from the in vitro cytotoxicity results. Practical implications The attempt can potentially meet the demand for flexible tubular scaffolds that ease the concerns such as availability of suitable organ donors. Originality/value 3D printing over accurate predefined templates to fabricate customized grafts gives novelty to the present method. Various customized scaffolds were compared with conventional cylindrical scaffold in terms of flexibility.


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