Graphene oxide and chitosan are promising materials for tissue regeneration. The present study explores a novel biomimetic mineralization route employing a graphene oxide (GO)–chitosan (CS) conjugate as a template material for the biomineralization of hydroxyapatite (HAP). Structural and morphological studies involving X-ray diffraction, Fourier transform infrared spectroscopy, and electron microscopy indicated that extensive mineralization occurred in the CS–GO conjugate system because of strong electrostatic interactions between the functional groups (carboxyl groups of GO and amino groups of CS) and calcium ions in the simulated body fluid (SBF). The combination of chitosan–graphene oxide conjugate and biomineralization was advantageous in favorably modulating cellular activity (osteoblast functions: cell attachment, proliferation, actin, vinculin and fibronectin expression). It is concluded that biomineralized hydroxyapatite in the HAP–CS–GO system induced homogeneous spatial osteoblastic cell growth and quantitatively (e.g. area) and qualitatively (e.g. mineral-to-matrix ratio) increased mineralization in relation to the HAP–GO system. The data underscore that covalent linkage of HAP to chitosan influences osteoblastic cell differentiation, mineralization, and cell growth. The proposed system and the revelation of fundamental insights merit consideration in tissue engineering.

We elucidate here process–structure–property relationships in implantable biomaterials processed by rapid prototyping approaches that are based on the principle of additive manufacturing. The conventional methods of fabrication of biomedical devices including freeze casting and sintering are limited because of difficulties in adaptation at the host site and mismatch in micro/macrostructure, mechanical and physical properties with the host tissue. Moreover, additive manufacturing has the advantage of fabricating patient-specific designs, which can be obtained from the computed tomography scan of the defect site. The discussion here comprises two parts – the first part briefly describes the evolution and underlying reasons that have led to 3D printing of scaffolds for tissue regeneration. The second part focuses on biocompatibility and mechanical properties of 3D scaffolds, fabricated by different approaches. The article concludes with a discussion on functionally graded scaffolds and vascularisation of 3D porous scaffolds that are envisaged to meet the requirements of the biomedical industry. In general, the mechanical properties of 3D printed scaffolds are governed by pore architecture, pore volume and percentage porosity. To ensure long-term endurance and the ability to withstand abrupt impact, it is important that the fabricated materials have a good combination of strength and energy absorption capability. While scaffolds with high interconnected porosity are preferred for tissue regeneration, such structures lack adequate mechanical strength and energy absorption capability. These mutually opposing requirements of high porosity and mechanical strength in conjunction with high energy absorption have hindered the application of 3D scaffolds as biomedical devices. In this regard, functionally graded 3D structures with high strength and energy absorption are potentially attractive for biomedical devices.