Nitrogen grafting onto polycarprolactone by a simple surface modification with atmospheric pressure glow discharge (Ar-APGD) and promoted neonatal human fibroblast growth

Chemical Immobilization of Carboxymethyl Chitosan on Polycaprolactone Nanofibers as Osteochondral Scaffolds

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.

Poly(ε-caprolactone)-Based Graft Copolymers: Synthesis Methods and Applications in the Biomedical Field: A Review

Synthetic biopolymers are attractive alternatives to biobased polymers, especially because they rarely induce an immune response in a living organism. Poly ε-caprolactone (PCL) is a well-known synthetic aliphatic polyester universally used for many applications, including biomedical and environmental ones. Unlike poly lactic acid (PLA), PCL has no chiral atoms, and it is impossible to play with the stereochemistry to modify its properties. To expand the range of applications for PCL, researchers have investigated the possibility of grafting polymer chains onto the PCL backbone. As the PCL backbone is not functionalized, it must be first functionalized in order to be able to graft reactive groups onto the PCL chain. These reactive groups will then allow the grafting of new reagents and especially new polymer chains. Grafting of polymer chains is mainly carried out by "grafting from" or "grafting onto" methods. In this review we describe the main structures of the graft copolymers produced, their different synthesis methods, and their main characteristics and applications, mainly in the biomedical field.

Utilizing Radio Frequency Plasma Treatment to Modify Polymeric Materials for Biomedical Applications

Studies that utilize radio frequency plasma modification as a strategy to tune the surface properties of polymeric constructs with the goal of enhancing their use as biomedical devices have grown considerably in number over the past decade. In this Review, we present the importance of plasma surface treatment to biomedical applications, including tissue engineering and wound healing. First, we introduce several key polymeric materials of interest for use as biomaterials, including those that are naturally derived and synthetic. We, then, provide an overview of possible outcomes of plasma modification, such as surface activation, etching, and deposition of a thin film, all of which can be used to alter the surface properties of a given polymer. Following this discussion, we review the methods used to characterize plasma-treated polymer surface properties, as well as the techniques used to evaluate their interactions with biological species of interest such as mammalian cells, bacteria, and blood components. To close, we provide a perspective on future outlooks of this exciting and rapidly evolving field.

Atmospheric Pressure Plasma Surface Treatment of Polymers and Influence on Cell Cultivation

Atmospheric plasma treatment is an effective and economical surface treatment technique. The main advantage of this technique is that the bulk properties of the material remain unchanged while the surface properties and biocompatibility are enhanced. Polymers are used in many biomedical applications; such as implants, because of their variable bulk properties. On the other hand, their surface properties are inadequate which demands certain surface treatments including atmospheric pressure plasma treatment. In biomedical applications, surface treatment is important to promote good cell adhesion, proliferation, and growth. This article aim is to give an overview of different atmospheric pressure plasma treatments of polymer surface, and their influence on cell-material interaction with different cell lines.

The Effect of Atmospheric Pressure Cold Plasma Application on Titanium Barriers: A Vertical Bone Augmentation

OBJECTIVE

The aim of the present, microcomputed tomographic (μCT) and histological study, was to evaluate the effect of surface modification by atmospheric pressure cold plasma (APCP) on vertical guided bone regeneration in a rabbit calvaria model.

MATERIAL-METHODS

The experimental study was conducted on 12 male New Zealand rabbits with healing periods of 45 and 90 days. Following surgical exposure of the calvarium, 4 customized titanium cylindricalders were fixed. Surface modification was achieved by application of APCP on 2 of cylinders (P+) in each calvarium and other cylinders were set as control (P-). In both experimental and control groups, one of the cylinders was filled with bone graft (G+) while the other one was left empty (G-). To evaluate short term effects, randomly selected 6 animals were sacrificed at the end of 45 days and remaining 6 animals were left for observing long term effects. Histological and μCT evaluations were used to examine new bone formation.

RESULTS

In μCT imaging; the bone volume was greater (P < 0.05) in grafted groups than nongrafted groups in both short and long term. The bone height values were significantly different in (P-G-) group than other groups (P < 0.05) in both evaluation periods. The histological evaluations revealed significant differences between P+G+ group and other groups but in long term both plasma treated groups revealed more bone formation than non plasma treated groups.

CONCLUSION

Modification of the surfaces of titanium cylinders by APCP treatment, accelerated the bone regeneration either bone graft used or not in a rabbit calvaria model.

Titanium surface modification by using microwave-induced argon plasma in various conditions to enhance osteoblast biocompatibility

Background

Titanium is a well proven implantable material especially for osseointegratable implants by its biocompatibility and anti-corrosive surface properties. Surface characteristics of the implant play an important role for the evolution of bone tissue of the recipient site. Among the various surface modification methods, plasma treatment is one of the promising methods for enhance biocompatibility. We made microwave-induced argon plasma at atmospheric pressure to improve in titanium surface biocompatibility.

Results

Various states of emission spectra from excited species-argon, nitrogen atoms and oxygen atoms were observed. The electron energy band structures are the unique characteristics of atoms and functional groups. Microwave-induced argon plasma treatment changed the titanium surface to be very hydrophilic especially on the 5 s short treatment and 30 s, 90 s long treatment samples that detected by contact angle measurement. MC3T3-E1 attachment and proliferation assay significantly increased in 5 s at short treatment, 30 s, and 90 s at long treatment after 5 days incubation.

Conclusions

Result indicated that microwave-induce argon plasma treatment would be an effective method to modify titanium surface for enhancing cell-material interactions.