Solid Freeform Techniques Application in Bone Tissue Engineering for Scaffold Fabrication

Solid freeform techniques are revolutionising technology with great potential to fabricate highly organized biodegradable scaffolds for damaged tissues and organs. Scaffolds fabricated via Solid freeform (SFF) techniques have more pronounced effect in bone tissue engineering. SFF techniques produce various types of scaffolds from different biomaterials with specific pore size, geometries, orientation, interconnectivity and anatomical shapes. Scaffolds needs to be designed from such biomaterials which can attach directly to natural tissues and mimic its properties, so ideally mechanical properties of scaffolds should be same as that of regenerating tissues for best results. The scaffolds designed without optimized mechanical properties would lead to the reduced nutrition diffusion within tissue engineered constructs (TECs) causing tissue necrosis. These scaffolds are mainly processed from ceramics and polymers like calcium phosphate, polydioxane, €-polycaprolactone, polylactic and polyglycolic acids etc. While, hydrogel scaffolds provide bridge for encapsulated cells and tissues to integrate with natural ECM. Likewise, 2D images from radiography were not sufficient for the prediction of the brain structure, cranial nerves, vessel and architecture of base of the skull and bones, which became possible using the 3D prototyping technologies. Any misrepresentation can lead to fatal outcomes. Biomodelling from these techniques for spinal surgery and preoperative planning are making its way toward successful treatment of several spinal deformities and spinal tumor. In this review we explored laser based and printing SFF techniques following its methodologies, principles and most recent areas of application with its achievements and possible challenges faced during its applications.

Evaluation of serum interleukin 6 and tumour necrosis factor alpha levels, and their association with various non-immunological parameters in renal transplant recipients

<p><b>INTRODUCTION</b>Renal transplant rejection involves both immunological and non-immunological factors. The objective of the present study was to investigate the association between immunological factors, such as serum interleukin 6 (IL-6) and tumour necrosis factor alpha (TNF-α), and non-immunological parameters, such as age, serum creatinine (SCr), creatinine clearance (CrCl) and dyslipidaemia, in renal transplant recipients (RTRs).</p><p><b>METHODS</b>This study included 90 RTRs and 90 healthy controls. Biochemical parameters, including serum IL-6 and TNF-α, were estimated using standard protocols. CrCl was calculated using the Cockroft-Gault equation, and the type of rejection was confirmed on biopsy. Student's t-test and univariate and multivariate analyses were performed using the Statistical Package for the Social Sciences for Windows version 15.</p><p><b>RESULTS</b>The mean levels of serum IL-6 and TNF-αwere significantly higher in RTRs than in the control group (p < 0.001). These parameters were also found to be significantly different between the transplant rejection (TR) and transplant stable (TS) groups (p < 0.001). CrCl was significantly decreased in the TR group when compared to the TS group (p < 0.001). The two cytokines, IL-6 and TNF-α, correlated significantly with all metabolic parameters, such as SCr, CrCl and dyslipidaemia. Multiple regression analysis showed that TNF-α and CrCl were the strongest predictors of IL-6.</p><p><b>CONCLUSION</b>We conclude that immunological factors, as well as non-immunological factors such as CrCl, SCr and dyslipidaemia, play important roles in the pathogenesis of graft rejection and renal graft dysfunction.</p>