Design of gelatin cryogel scaffolds with the ability to release simvastatin for potential bone tissue engineering applications.

Tissue engineering aims to improve or restore damaged tissues by using scaffolds, cells and bioactive agents. In tissue engineering, one of the most important concepts is the scaffold because it has a key role in keeping up and promoting the growth of the cells. It is also desirable to be able to load these scaffolds with drugs that induce tissue regeneration/formation.

Electrospun nanofiber mats caged the mammalian macrophages on their surfaces and prevented their inflammatory responses independent of the fiber diameter.

Poly-ε-caprolactone (PCL) has been widely used as biocompatible materials in tissue engineering. They have been used in mammalian cell proliferation to polarization and differentiation. Their modified versions had regulatory activities on mammalian macrophages in vitro.

Electrospun Nanofibers for Biomedical, Sensing, and Energy Harvesting Functions.

The process of electrospinning is over a century old, yet novel material and method achievements, and later the addition of nanomaterials in polymeric solutions, have spurred a significant increase in research innovations with several unique applications. Significant improvements have been achieved in the development of electrospun nanofibrous matrices, which include tailoring compositions of polymers with active agents, surface functionalization with nanoparticles, and encapsulation of functional materials within the nanofibers. Recently, sequentially combining fabrication of nanofibers with 3D printing was reported by our group and the synergistic process offers fiber membrane functionalities having the mechanical strength offered by 3D printed scaffolds.

Impact of injectable chitosan cryogel microspherescaffolds on differentiation and proliferation of adiposederived mesenchymal stem cells into fat cells.

Difficulty in the clinical practice of stem cell therapy is often experienced in achieving desired target tissue cell differentiation and migration of stem cells to other tissue compartments where they are destroyed or die. This study was performed to evaluate if mesenchymal stem cells (MSCs) may differentiate into desired cell types when injected after combined with an injectable cryogel scaffold and to investigate if this scaffold may help in preventing cells from passing into different tissue compartments. MSCs were obtained from fat tissue of the rabbits as autografts and nuclei and cytoplasms of these cells were labeled with BrdU and PKH26.

Differential anti-inflammatory properties of chitosan-based cryogel scaffolds depending on chitosan/gelatin ratio.

Chitosan/gelatine-based materials have been widely used as biocompatible scaffolds in the tissue engineering field. Chitosan suppresses the inflammatory activities of macrophages whereas gelatine induces inflammatory cytokine production by these cells. Cryogel form of the scaffolds created an effect that was mostly dominated by chitosan activity.

Development of Hypericum perforatum oil incorporated antimicrobial and antioxidant chitosan cryogel as a wound dressing material.

In this study, a herbal infused oil (Hypericum perforatum, HP) incorporated chitosan (CS) cryogel as a wound dressing material was produced in order to be used in wound healing process. The main strategy is to combine the traditional perspective of using medicinal oils with polymeric scaffolds manufactured by an engineering approach to fabricate a potential tissue engineering product that provides both new tissue formation and wound healing. The scaffolds manufactured by cryogelation were soft, spongy, highly porous, physically stable, elastic and could be easily cut in any desired shape.

Stem cells combined 3D electrospun nanofibrous and macrochannelled matrices: a preliminary approach in repair of rat cranial bones.

Repair of cranial bone defects is an important problem in the clinical area. The use of scaffolds combined with stem cells has become a focus in the reconstruction of critical-sized bone defects. Electrospinning became a very attracting method in the preparation of tissue engineering scaffolds in the last decade, due to the unique nanofibrous structure of the electrospun matrices.

Effect of crosslinking methods on the structure and biocompatibility of polyvinyl alcohol/gelatin cryogels.

In this study, polyvinyl alcohol (PVA) and gelatin based cryogels were prepared by crosslinking chemically or physically for tissue engineering applications. Different PVA/Gelatin ratios (100:0, 90:10, 70:30, 50:50) and crosslinking methods have been used to prepare cryogels; chemical and physical structure of the prepared matrices were analysed by FTIR and SEM; swelling and degradation profiles were followed. Chemical and physical crosslinking was obtained by using glutaraldehyde as crosslinker and by applying freeze thawing cycle, respectively.

Thermoresponsive biodegradable HEMA-lactate-Dextran-co-NIPA cryogels for controlled release of simvastatin.

Abstract NIPA and HEMA-lactate-Dextran-based biodegradable and thermoresponsive cryogels were synthesized at different compositions by cryogelation. Chemical and morphological properties of the HEMA-lactate-Dextran-co-NIPA cryogel matrices were demonstrated by FTIR, SEM, and ESEM. Thermoresponsivity of the prepared cryogels was investigated by DSC, imaging NMR, and swelling studies.

Gelatin- and hydroxyapatite-based cryogels for bone tissue engineering: synthesis, characterization, in vitro and in vivo biocompatibility.

The aim of this study was the synthesis and characterization of gelatin- and hydroxyapatite (osteoconductive component of bone)-based cryogels for tissue-engineering applications. Preliminary in vitro and in vivo biocompatibility tests were conducted. Gelatin- and hydroxyapatite-based cryogels of varying concentrations were synthesized using glutaraldehyde as the crosslinking agent.

Stem cell suspension injected HEMA-lactate-dextran cryogels for regeneration of critical sized bone defects.

HEMA-Lactate-Dextran cryogel scaffolds were produced by cryogelation. Mesencyhmal stem cells (MSC) were isolated from rat bone marrow. Critical sized cranial bone defects were created in rat cranium.

Three-dimensional ingrowth of bone cells within biodegradable cryogel scaffolds in bioreactors at different regimes.

Three-dimensional cell ingrowth within biodegradable cryogel scaffolds made of cross-linked 2-hydroxyethyl methacrylate (HEMA)-lactate-dextran with interconnected macropores was studied in bioreactors at different regimes (static, perfusion, and compression-perfusion). An osteoblast-like cell line (MG63) was used in these studies. The samples taken after selected times from the bioreactors were examined by microscopy techniques (light, SEM, TEM, and laser scanning confocal).

Tissue responses to novel tissue engineering biodegradable cryogel scaffolds: an animal model.

Biodegradable macroporous cryogels with highly open and interconnected pore structures were produced from dextran modified with oligo L-lactide bearing hydroxyethylmethacrylate (HEMA) end groups in moderately frozen solutions. Tissue responses to these novel scaffolds were evaluated in rats after dorsal subcutaneous implantation, iliac submuscular implantation, auricular implantation, or in calvarial defect model. In no case, either necrosis or foreign body reaction was observed during histological studies.

In vivo performance of simvastatin-loaded electrospun spiral-wound polycaprolactone scaffolds in reconstruction of cranial bone defects in the rat model.

Reconstruction of large bone defects is still a major problem. Tissue-engineering approaches have become a focus in regeneration of bone. In particular, critical-sized defects do not ossify spontaneously.

Cryogelation for preparation of novel biodegradable tissue-engineering scaffolds.

2-Hydroxyethyl methacrylate-L-lactate (HEMA-LLA) and HEMA-L-lactate-dextran (HEMA-LLA-D) were synthesized. 1H-NMR confirmed the formation of these oligomers and macromers. Cryogels with different pore structures were prepared using different amounts of HEMA, HEMA-LLA and HEMA-LLA-D by a cryogelation technique.

Electrospun matrices made of poly(alpha-hydroxy acids) for medical use.

Biomaterials are widely used in diverse applications as substances, materials or important elements of biomedical devices. Biodegradable polymers, both natural and synthetic, have been utilized in applications in which they act as temporary substitutes. Poly(alpha-hydroxy acids), especially lactic acids and glycolic acid and their copolymers with epsilon-caprolactone, are the most widely known and used among all biodegradable polymers.