Anuj Bellare - Academia.edu (original) (raw)

Papers by Anuj Bellare

The Journal of Bone and Joint Surgery, 2002

Ceramics International, Jun 1, 2021

International Journal of Nanomedicine, Feb 1, 2017

An easier method for constructing the hierarchical micro-/nano-structures on the surface of denta... more An easier method for constructing the hierarchical micro-/nano-structures on the surface of dental implants in the clinic is needed. In this study, three different titanium surfaces with microscale grooves (width 0.5-1, 1-1.5, and 1.5-2 μm) and nanoscale nanoparticles (diameter 20-30, 30-50, and 50-100 nm, respectively) were obtained by treatment with different concentrations of hydrofluoric acid (HF) and at different etching times (1%, 3 min; 0.5%, 12 min; and 1.5%, 12 min, respectively; denoted as groups HF1, HF2, and HF3). The biological response to the three different titanium surfaces was evaluated by in vitro human bone marrow-derived mesenchymal stem cell (hBMMSC) experiments and in vivo animal experiments. The results showed that cell adhesion, proliferation, alkaline phosphatase activity, and mineralization of hBMMSCs were increased in the HF3 group. After the different surface implants were inserted into the distal femurs of 40 rats, the bone-implant contact in groups HF1, HF2, and HF3 was 33.17%±2.2%, 33.82%±3.42%, and 41.04%±3.08%, respectively. Moreover, the maximal pullout force in groups HF1, HF2, and HF3 was 57.92±2.88, 57.83±4.09, and 67.44±6.14 N, respectively. The results showed that group HF3 with large micron grooves (1.5-2.0 μm) and large nanoparticles (50-100 nm) showed the best bio-functionality for the hBMMSC response and osseointegration in animal experiments compared with other groups.

Journal of orthopaedics, May 1, 2021

Purposeto review advances and clinical performance of polyethylene in total joint arthroplasty, s... more Purposeto review advances and clinical performance of polyethylene in total joint arthroplasty, summing up historical problems and focusing on the latest innovations.Methodssearch for medical grade Ultra-High-Molecular-Weight-Polyethylene (UHMWPE); Data Sources: PubMed, Scopus, Cochrane Library.Resultsthe increasing number of joint arthroplasties and high-activity patients led to progressive developments of bearing surfaces to improve performance and durability. Different strategies such as crosslinking UHMWPE (HXLPE) and the addition of vitamin-E (HXLPE) have been tested to improve wear and oxidation resistance.ConclusionRecent innovations about UHMWPE showed improvements either for hip and knee, with the potential of long-term survivorship.

cosp, 2002

ABSTRACT In order to address the effects of microgravity on living tissue, we must examine and un... more ABSTRACT In order to address the effects of microgravity on living tissue, we must examine and understand tissue response on a molecular level. Doing so requires the development of quantitative techniques for characterizing tissue behavior on the micrometer scale under both normal and reduced gravitational fields. It has been demonstrated that small angle light scattering holds great promise in this regard. Small angle light scattering (SALS) has been used to probe tissue microstructure on the micron and sub-micron length scales. Quantitative information on feature geometry, dimension and orientation was obtained. Here, we discuss the application of small angle light scattering techniques to the study of connective tissue. Two terrestrial situations relevant to future microgravity studies were considered: the anisotropic behavior of collagen fibers in rabbit tendon in response to increasing load; and, the variation in collagen structure in healthy and arthritic human cartilage. SALS allowed quantitative determination of both fiber diameter and degree of orientation, providing a level of information beyond that obtainable by light and electron microscopies. The primary advantages of SALS over these techniques lies in its quantitative nature and reduced sample preparation requirements. SALS requires neither vacuum or the use of dyes, eliminating important potential sources of artifacts. Results from these studies compare favorably with microscopy studies and demonstrate the importance of the quantitative nature of the technique. In addition, these results also demonstrate the potential of SALS for providing quantitative analysis of effects of microgravity on structural and connective tissue.

Uncontrolled postpartum hemorrhage (PPH) is the most common cause of maternal morbidity and morta... more Uncontrolled postpartum hemorrhage (PPH) is the most common cause of maternal morbidity and mortality worldwide, with most cases of death and disability mainly in resource poor settings. Placement of a uterine balloon tamponade (UBT) is a recognized life-saving intervention in these circumstances. A UBT device is a balloon attached to a semi-rigid large bore catheter that acts as both an introducer and as a channel to rapidly inflate the balloon once it is placed into the uterine cavity. Reports on patient outcomes associated with commercial UBT devices are encouraging, however, their high cost (up to$400 USD) is a barrier to implementation across resource-poor settings. The ESM-UBT device is an ultra-low-cost condom-catheter UBT designed to be a quality and affordable device for scale in resource poor areas (Figure 1). The purpose of this study was to comprehensively evaluate the mechanical properties of this device, in advance of Regulatory evaluation. The evaluated mechanical properties are expected to be effective on the function of the device in clinic.

Bubble Continuous Positive Airway Pressure (bCPAP) is a life-saving intervention for children and... more Bubble Continuous Positive Airway Pressure (bCPAP) is a life-saving intervention for children and newborns with respiratory distress. A typical bCPAP circuit consists of a source of air with a blender that adjusts its oxygen concentration, a nasal interface that delivers the gas to the patient, and a water reservoir that generates pressure. The nasal interface and water reservoir can be sourced at low cost, but all existing blenders are high cost and require either compressed medical air (typically unavailable in low resource settings) or electricity, which can be unreliable in these settings. Oxygen is often the only pressurized gas available. Therefore, some improvised devices will give the patient pure oxygen, which is harmful to neonates' eyes, lungs, and brain. We aimed to create an ultra-low-cost, high quality bCPAP system that overcomes these barriers to scale.

Aims: In recent years, radiation crosslinking has become an important processing step in the manu... more Aims: In recent years, radiation crosslinking has become an important processing step in the manufacture of ultra-high molecular weight polyethylene (PE) components of joint replacement prostheses due to its associated high wear resistance. Gamma or electron beam radiation treatment is usually followed by a heating step, either complete melting or annealing of PE close to but below the melting temperature for a specific time duration. The heat treatment is performed to decrease free radical concentration within the crystalline lamellae in order to make PE more oxidation resistant. In this study, we hypothesized that high pressure processing of PE would be advantageous if it is performed only after irradiation and quenching of free radicals and that it would be detrimental if it preceded irradiation. We used accelerated oxidation, mechanical tests and wear tests to show Methods: Ram-extruded rod stock of GUR 1050 PE (Ticona, Bayport, TX) was purchased from MediTECH Medical Polymers (...

International Journal of Radiation Oncology*Biology*Physics, 2017

respectively) but did not change significantly in CFRT patients. IL-15 increased significantly du... more respectively) but did not change significantly in CFRT patients. IL-15 increased significantly during treatment in the CFRT (p Z 0.01) and ChRT (p<0.001) patients but not in the SBRT group. ChRT patients exhibited the most dynamic changes in CK expression, with significant decreases in IP-10 (p < 0.001), sCD40l (pZ0.003), and IL-2 (pZ0.04) as well as the previously noted changes in IL-8 and IL-15. Median TGF-B1 values increased in the SBRT and CFRT groups but decreased in the ChRT group, although these changes were not statistically significant. Conclusion: Treatment scheme appeared to be significantly associated with differing cytokine expression patterns in patients undergoing radiation for NSCLC. Combined ChRT patients appeared to have the greatest variability in multiple CKs including IP-10, sCD40l, IL-2, IL-8, and IL-15. Differences were also seen among the treatment groups in IL-8 and IL-15. Further study is needed to determine whether CK expression patterns can serve as an immune biomarker for outcomes in NSCLC.

Frontiers in Bioengineering and Biotechnology, 2016

Macromolecules, 2002

The grain structure in lamellar block copolymer samples undergoing a disorder-to-order transition... more The grain structure in lamellar block copolymer samples undergoing a disorder-to-order transition was studied by a combination of depolarized light scattering (DPLS) and transmission electron microscopy (TEM). The 4-fold symmetry of the DPLS profiles indicated the presence of anisotropic grains. A pattern recognition algorithm for analyzing the TEM micrographs of samples partially filled with anisotropic, ordered grains was developed. The volume fractions of sample occupied by ordered grains determined from light scattering and electron microscopy are in reasonable agreement. Both methods indicate that, on average, the characteristic length of the grains in the direction perpendicular to the lamellar planes was a factor of 2 larger than that in the plane of the lamellae. The absolute magnitudes of grain sizes determined by light scattering are about 50% larger than those determined by microscopy.

International Journal of Nanomedicine, 2014

Background: Titanium surfaces play an important role in affecting osseointegration of dental impl... more Background: Titanium surfaces play an important role in affecting osseointegration of dental implants. Previous studies have shown that the titania nanotube promotes osseointegration by enhancing osteogenic differentiation. Only relatively recently have the effects of titanium surfaces with other nanostructures on osteogenic differentiation been investigated. Methods: In this study, we used NaOH solutions with concentrations of 2.5, 5.0, 7.5, 10.0, and 12.5 M to develop a simple and useful titanium surface modification that introduces the nanonetwork structures with titania nanosheet (TNS) nanofeatures to the surface of titanium disks. The effects of such a modified nanonetwork structure, with different alkaline concentrations on the osteogenic differentiation of rat bone marrow mesenchymal stem cells (BMMSCs), were evaluated. Results: The nanonetwork structures with TNS nanofeatures induced by alkali etching markedly enhanced BMMSC functions of cell adhesion and osteogenesis-related gene expression, and other cell behaviors such as proliferation, alkaline phosphatase activity, extracellular matrix deposition, and mineralization were also significantly increased. These effects were most pronounced when the concentration of NaOH was 10.0 M. Conclusion: The results suggest that nanonetwork structures with TNS nanofeatures improved BMMSC proliferation and induced BMMSC osteogenic differentiation. In addition, the surfaces formed with 10.0 M NaOH suggest the potential to improve the clinical performance of dental implants.

Polymer Degradation and Stability

Academic Journal of Pediatrics & Neonatology, 2020

supplemental oxygen to neonates [2-7]. While supplemental oxygen is often important for these pat... more supplemental oxygen to neonates [2-7]. While supplemental oxygen is often important for these patients, high concentrations (hyperoxia) may be harmful [8]. Bronchopulmonary dysplasia and retinopathy of prematurity are two major adverse effects of administering high concentrations of inspired oxygen to preterm

Introduction: Oxidation in ultra-high molecular weight polyethylene (UHMWPE) due to sterilization... more Introduction: Oxidation in ultra-high molecular weight polyethylene (UHMWPE) due to sterilization by gamma-radiation in air to a dose of 25-37 kGy is known to lead to embrittlement and delamination wear in tibial components of total knee replacement prostheses [1] and increased particulate wear in acetabular cups of total hip replacement prostheses [2]. It has been shown that incorporating antioxidants into UHMWPE, such as Vitamin E (or a-tocopherol), imparts oxidation-resistance to UHMWPE, thereby decreasing delamination wear [3] as well as particulate wear [4] in irradiated, aged UHMWPE. In this study, we hypothesized that premixing Vitamin E would impart oxidation resistance to irradiated UHMWPE during shelf aging regardless of irradiation dose. Real-time shelf aging of UHMWPE containing various concentrations of Vitamin E, conducted over a 2-year period, showed that Vitamin E induced concentrationdependent oxidation resistance in UHMWPE and could thereby be a valuable additive f...

ABSTRACT Poly(methyl methacrylate) (PMMA) based orthopaedic bone cements contain 1-3 Pim size rad... more ABSTRACT Poly(methyl methacrylate) (PMMA) based orthopaedic bone cements contain 1-3 Pim size radiopacifier particles. Incomplete dispersion of these particles leads to the presence of 50-200 pm size agglomerates. These large defects are sites of high-stress ...