Aim: The functionalization and characterization of antibacterial nanoceria with folic acid (FA) and elucidation of their in vivo wound-healing application. Materials & methods: Functionalization of nanoceria were done with FA using a chemical method and their antibacterial activity, cellular biocompatibility and in vivo wound-healing application were evaluated. Results: The functionalization of nanoceria with FA was done with 10-20 nm size and -20.1 mV zeta potential. The nanoformulation showed a bacteriostatic effect along with biocompatibility to different cell lines; 0.1% w/v spray of FA-nanoceria demonstrated excellent wound-healing capacity within 14 days in a Wister rat model. Conclusion: The antioxidant and reactive oxygen species scavenging activity of the FA-nanoceria make it a promising therapeutic agent as a unique spray formulation in wound-healing applications.
The emergence of chronic wounds is a main reason for mortality in patients with diabetes and other severe pathological complications. Advances in the use of nanotechnology have resulted in beneficial technology for tailoring of pharmacokinetic properties of different drug-delivery vehicles for different biomedical applications. In this study, folic acid (FA) functionalized nanoceria (FA-nanoceria) were formulated and their potential efficacy in the wound-healing process was explored. The nanoformulation showed a remarkable bacteriostatic effect on both Gram-negative and Gram-positive bacteria. In vitro cell line studies showed satisfactory biocompatibility in three different types of cell lines. In addition, a 0.1% w/v spray of FA-nanoceria was applied to full-thickness wounds in an in vivo mice model where it demonstrated excellent wound-healing capacity within 14 days. The combined antioxidant and reactive oxygen species scavenging activity of both the FA and nanoceria makes FA-nanoceria a promising therapeutic agent as a unique spray formulation in wound-healing applications.
Antioxidants , Folic Acid , Rats , Animals , Folic Acid/chemistry , Rats, Wistar , Antioxidants/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry
The main objective of this study is to perform an abrasive wear resistance study of UMHWPE and XLPE by using different grades of abrasive paper (grade 100 (190 µm), grade 220 (50 µm), and grade 400 (40 µm)) with minor (10 N) and major (15 N) loading conditions. In this article, wear performance of the UMHWPE and XLPE materials compared to the bio-tribological data as reported earlier in the clinical studies has been investigated. The experimental result shows that the loss of materials for the XLPE was much higher than the UHMWPE under similar loading conditions. UHMWPE shows a 34% reduction in wear at minor loading conditions and a 53% reduction in wear at major loading conditions. From experimental results it was concluded that Cross-link PE has better wear resistance than UHMWPE in minor wear conditions, whereas UHMWPE shows better wear resistance under major loading conditions. Based upon these results, UHMWPE and XLPE have been recommended for use as bearing materials in orthopedics. The experimental results of this study were validated using results from the available literature.
The objective of the present work is to carry out analytical and finite element analysis for commonly used coating materials for micro-milling applications on high-speed steel substrate and evaluate the effects of different parameters. Four different coating materials were selected for micro-milling applications: titanium nitride (TiN), diamond-like carbon (DLC), aluminium titanium nitride (AlTiN) and titanium silicon nitride (TiSiN). A 3D finite element model of coating and substrate assembly was developed in Abaqus to find the Hertzian normal stress when subjected to normal load of 4 N, applied with the help of a rigid ball. The radius of the rigid ball was 200 µm. For all the coating materials, the length was 3 mm, the width was 1 mm, and the thickness was 3 µm. For the high-speed steel substrate, the length was 3 mm, the width was 1 mm, and the thickness was 50 µm. Along the length and width, coating and substrate both were divided into 26 equal parts. The deformation behaviour of all the coating materials was considered as linear-elastic and that of the substrate was characterized as elastic-plastic. The maximum normal stress developed in the FEA model was 12,109 MPa. The variation of the FEA result from the analytical result (i.e., 12,435.97 MPa is 2.63%) which is acceptable. This confirms that the FEA model of coating-substrate assembly is acceptable. The results shows that the TiSiN coating shows least plastic equivalent strain in the substrate, which serves the purpose of protecting the substrate from plastic deformation and the TiSiN of 3 micron thickness is the most optimum coating thickness for micro-milling applications.
The main objective of this article is to perform the turning operation on an EN36B steel work-billet with a tungsten carbide tool, to study the optimal cutting parameters and carry out an analysis of flank-wear. Experimental and simulation-based research methodology was opted in this study. Experimental results were obtained from the lab setup, and optimisation of parameters was performed using RSM (response surface methodology). Using RSM, cutting-tool flank-wear was optimised, and the cutting parameters which affect the flank wear were determined. In results main effect plot, contour plot, the surface plot for flank-wear and forces (Fx, Fy and Fz) were successfully obtained. It was concluded that tool flank-wear is affected by depth of cut, and that flank-wear generally increases linearly with increasing cutting-speed, depth of cut and feed-rate. To validate the obtained results, predicated and measured values were plotted and were in very close agreement, having an accuracy level of 96.33% to 98.92%.
The current work focuses on the fabrication of high-molecular-weight stereocomplex poly(lactic acid)/nanohydroxyapatite (sPLA/n-HAP)-based bionanocomposite for three-dimensional (3D)-printed orthopedic implants and high-temperature engineering applications. To achieve the same, n-HAP is grafted with poly(d-lactic acid) (PDLA) via in situ ring-opening polymerization of d-lactide, followed by blending with poly(l-lactic acid) (PLLA), which yields sPLA/n-HAP biocomposite with improved storage modulus even at temperatures higher than 140 °C. X-ray diffraction and calorimetric analysis ensure the presence of 100% stereocomplex crystallites of biocomposite along with significant improvement in the melting temperature (â¼227 °C). Noteworthy improvements in the mechanical and gas-barrier properties of the developed biocomposites are achieved due to the uniform dispersion of n-HAP (â¼60 nm) confirmed by morphological studies. An unusual improvement in elongation at break (â¼130% at 1 wt % HAP loading) makes this composite a toughened material. However, the tensile strength is improved by â¼16%, whereas oxygen permeability and water vapor transmission rate are found to reduce by â¼48 and â¼34%, respectively. Interestingly, the developed material is processed as monofilament, followed to 3D printing to yield a middle phalanx bone as a representative example of orthopedic implants. In vitro studies reveal that cell adhesion and proliferation on the surface of the developed biocomposite support its biocompatible nature. This signifies the possible future aspects of the material in commercial biomedical and high-temperature engineering applications.
