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The field of tissue engineering is an emerging discipline which applies the basic principles of life sciences and engineering to repair and restore living tissues and organs. The purpose of this study was to investigate the effect of cold and non-thermal plasma surface modification of poly (ϵ-caprolactone) (PCL) scaffolds on fibroblast cell behavior. Nano-fiber PCL was fabricated through electrospinning technique, and some fibers were then treated by cold and non-thermal plasma. The cell-biomaterial interactions were studied by culturing the fibroblast cells on nano-fiber PCL. Scaffold biocompatibility test was assessed using an inverted microscope. The growth and proliferation of fibroblast cells on nano-fiber PCL were analyzed by MTT viability assay. Cellular attachment on the nano-fiber and their morphology were evaluated using scanning electron microscope. The result of cell culture showed that nano-fiber could support the cellular growth and proliferation by developing three-dimensional topography. The present study demonstrated that the nano-fiber surface modification with cold plasma sharply enhanced the fibroblast cell attachment. Thus, cold plasma surface modification greatly raised the bioactivity of scaffolds.

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Cell attachment and differentiation on biomaterials might be enhanced by surface modification techniques. The main aim of this study was to improve stem cell/material interaction by pressure cold atmospheric plasma (CAP). We developed a combination of electrospun poly (ε‐caprolactone) (PCL)‐chitosan (CTS) and PCL‐carboxy methyl chitosan (CMC) scaffolds. In order to make nanofiber surfaces more appropriate for mesenchymal stem cell (MSC) attachment and proliferation, CAP was used. Proliferation and cartilage differentiation of MSCs were then evaluated during 21 days. Biocompatibility test, scanning electron microscopy (SEM) analysis, 3‐[4,5‐dimethylthiazol‐2yl]‐2, 5‐diphenyl tetrazolium bromide (MTT) and 4′,6‐diamidino‐2‐phenylindole (DAPI) staining were performed. After 21 days, induction of cartilage differentiation was approved through expression of SRY‐Box 9 (SOX9) and collagen type II (COL2) genes by reverse transcription polymerase chain reaction (RT‐PCR), and COL2 protein expression was accordingly confirmed by immunocytochemistry (ICC). Thus, our data showed the PCL/CMC scaffolds can support and induce the differentiation of MSC to cartilage‐like cells.

One of the determinant factors for successful bioengineering is to achieve appropriate nano-topography and three-dimensional substrate. In this research, polycaprolactone (PCL) nano-fibrous mat with different roughness modified with O2 plasma was fabricated via electrospinning. The purpose of this study was to evaluate the effect of plasma modification along with surface nano-topography of mats on the quality of human fibroblast (HDFs) and osteoblast cells (OSTs)-substrate interaction. Surface properties were studied using scanning electron microscopy (SEM), atomic force microscopy (AFM), contact angle, Fourier-transformation infrared spectroscopy. We evaluated mechanical properties of fabricated mats by tensile test. The viability and proliferation of HDFs and OSTs on the substrates were followed by 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT). Mineralization of the substrate was determined by alizarin red staining method and calcium content of OSTs was determined by calcium content kit. Cells morphology was studied by SEM analysis. The results revealed that the plasma-treated electrospun nano-fibrous substrate with higher roughness was an excellent designed substrate. A bioactive topography for stimulating proliferation of HDFs and OSTs is to accelerate the latter’s differentiation time. Therefore, the PCL substrate with high density and major nano-topography were considered as a bio-functional and elegant bio-substrate for tissue regeneration applications.

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Donor numbers (DNs) of binary mixtures of acetonitrile with methanol, ethanol, ethylene glycol, 1-butanol, and tert-butanol were calculated in the whole range of mole fractions based on 23 Na-NMR chemical shift of sodium perchlorate dissolved in solvent. Data showed positive deviation from hypothetical linear ideal behavior. Solvatochromic parameters including empirical polarity, dipolar/polarizability, hydrogen bond donor, and hydrogen bond acceptor of the solvent mixtures were spectrophotometrically measured in order to investigate the correlations among parameters. The trend of data showed the preferential solvation along with synergistic behavior in some of mixtures. Applying preferential solvation model confirmed the solvent-solvent interactions in the studied binary mixtures. Although no reasonable correlation was observed between DN with solvatochromic parameters, dual-parameters regressions showed that some of solvatochromic parameters have linear relationships with DN. The presence of solvent-solvent interactions in the media caused that the solvent mixtures didn't follow the known correlations as reported before.

Carboxymethyl chitosan (CMC) as a bio-based osteochondral inductive material was chemically immobilized on the surface of polycaprolactone (PCL) nanofibers to fabricate scaffolds for osteochondral tissue engineering applications. The chemical immobilization process included the aminolysis of ester bonds and bonding of the primary amines with glutaraldehyde as a coupling agent. The SEM and FTIR results confirmed the successfulness of the CMC immobilization. The fabricated scaffolds presented cell viabilities of > 82% and supported the attachment and proliferation of the human bone marrow mesenchymal stem cells (hBM-MSCs). The CMC-immobilized scaffolds concentration dependently induced the diverse osteochondral differentiation pathways for the hBM-MSCs without using any external differential agents. According to the Alcian Blue and Alizarin Red staining and immunocytochemistry results, scaffolds with a higher content of CMC presented more chondro-inductivity and less osteoinductivity. Thus, the CMC-immobilized scaffolds can be employed as great potential candidates for osteochondral tissue engineering applications.