Surface Modification of Polymeric Scaffolds for Tissue Engineering Applications

Abstract

For a long time, physicians have been pursuing the challenges of limb loss, fixing dysfunctional body parts and cosmetic surgery using both natural and synthetic materials. Synthetic polymers, especially the saturated homopolymers, have been found to be suitable for such applications as they have high tensile strength, which can also be varied as desired, due to the presence of strong intermolecular forces. This allows easy fabrication of macroporous scaffolds from them, which have special surgical and suturing advantages earning them decades-long recognition in medical science. However, they have disadvantages, such as slow integration with the actively growing tissue due to their hydrophobic nature, and several surface modification techniques have been proposed to combat this limitation. Unfortunately, during some of these surface modification treatments, many of the above listed critical properties of these polymers get compromised, making the need for a highly suitable and convenient surface modification technique most sought after. This review will elucidate the background of bioimplants and describe various available materials. It will also discuss the pros and cons of most popularly used materials to fabricate 3D scaffolds and challenges to improve their surface characteristics. Different modification techniques to make the scaffold/implant surface cell friendly will be revised. Finally, this review will present the plasma treatment based layer-by-layer assembly of nanoparticle–small molecule conjugates on polymer scaffolds as an efficacious method to improve cell adhesion and proliferation. The organization of the review is as follows: (1) tabulation of biomaterials used for different purposes, organs, and systems, (2) categorization of polymers according to their physical and material properties, (3) advantages and disadvantages of the polymers being used as scaffold/biomaterial, (4) available surface modification techniques and their pros and cons, and (5) proposing the new plasma treatment-based layer-by-layer assembly nanoparticle–small molecule conjugate on polymer scaffolds as an efficacious method to improve cell adhesion and proliferation. Plastic/polymeric materials, for their excellent material properties and bioinactive nature, are being widely used in tissue engineering applications. Sometimes, these pose problems due to their slow integration with live tissues. Surface modification, keeping their strength and durability intact, would be a solution to this problem. Unfortunately, carrying out surface modification is cumbersome in some case while in case of others, the surface modifications are of transient nature. This review narrates the key reasons behind surface biofriendliness (of a material), techniques available for surface modification, and presents a simple layer-by-layer surface modification technique involving biocompatible ingredients (like gold nanoparticle, simple amino acid) as an alternative for better cell adhesion and proliferation.