Assessment of zinc inadequacy among tribal adolescent population of central India - A cross-sectional study.

Background & objectives: Zinc is a crucial micronutrient in adolescence, required for promoting growth and sexual maturation. Adolescents of some tribes may be at high risk of zinc deficiency due to dietary inadequacy and poor bioavailability of zinc from plant-based diets. This study aimed to evaluate the risk of zinc deficiency by estimating prevalence of inadequate zinc intake, prevalence of low serum zinc and stunting among tribal adolescents. Methods: A cross-sectional community-based survey was conducted among adolescents (10-19 yr) in three purposively selected districts where Bhil, Korku and Gond tribes were in majority. Structured data collection instrument comprising information about sociodemographic characteristics and dietary recall data was used. Anthropometric assessment was conducted by standardized weighing scales and anthropometry tapes, and blood sample was collected from antecubital vein into trace element-free vacutainers. Serum zinc was estimated using an atomic absorption spectrophotometer. Results: A total of 2310 households were approached for participation in the study, of which 2224 households having 5151 adolescents participated. Out of these enlisted adolescents, 4673 responded to dietary recall (90.7% response rate). Anthropometry of 2437 participants was carried out, and serum zinc was analyzed in 844 adolescents. The overall prevalence of dietary zinc inadequacy was 42.6 per cent [95% confidence interval (CI) 41.2 to 44.1] with reference to the estimated average requirement suggested by International Zinc Nutrition Consultative Group (IZiNCG) and 64.8 per cent (95% CI 63.4 to 66.2) with Indian Council of Medical Research-recommended requirements. Stunting was observed in 29 per cent (95% CI 27.2 to 30.8) participants. According to IZiNCG cut-offs, low serum zinc was detected in 57.5 per cent (95% CI 54.1 to 60.8) of adolescents, whereas it was 34.4 per cent (95% CI: 31.2-37.5) according to the national level cut-off. Interpretation & conclusions: Risk of dietary zinc inadequacy and low serum zinc concentration amongst adolescents of the Gond, Bhil and Korku tribes is a public health concern.

Pulp-Dentin Tissue Healing Response: A Discussion of Current Biomedical Approaches.

Dental pulp tissue exposed to mechanical trauma or cariogenic process results in root canal and/or periapical infections, and conventionally treated with root canal procedures. The more recent regenerative endodontic procedure intends to achieve effective root canal disinfection and adequate pulp-dentin tissue regeneration; however, numerous limitations are reported. Because tooth is composed of vital soft pulp enclosed by the mineralized hard tissue in a highly organized structure, complete pulp-dentin tissue regeneration has been challenging to achieve. In consideration of the limitations and unique dental anatomy, it is important to understand the healing and repair processes through inflammatory-proliferative-remodeling phase transformations of pulp-dentin tissue. Upon cause by infectious and mechanical stimuli, the innate defense mechanism is initiated by resident pulp cells including immune cells through chemical signaling. After the expansion of infection and damage to resident pulp-dentin cells, consequent chemical signaling induces pluripotent mesenchymal stem cells (MSCs) to migrate to the injury site to perform the tissue regeneration process. Additionally, innovative biomaterials are necessary to facilitate the immune response and pulp-dentin tissue regeneration roles of MSCs. This review highlights current approaches of pulp-dentin tissue healing process and suggests potential biomedical perspective of the pulp-dentin tissue regeneration.

Encapsulation of Human Islets Using a Biomimetic Self-Assembled Nanomatrix Gel for Protection against Cellular Inflammatory Responses.

The major concern of pancreatic islet transplantation is that the implanted islets are exposed to the immune system of the recipient. To overcome this challenge, the peptide amphiphile (PA) nanomatrix gel was used for immunoisolation of islets through microencapsulation. The PA can self-assemble to form a nanomatrix gel with an extracellular matrix-mimicking, islet nurturing microenvironment and a semipermeable immune barrier. In this study, the islet protective effect of the PA nanomatrix gel was evaluated by coculture of PA-encapsulated human islets with differentiated U937 cells (human monocyte cell-line) for 3 and 7 days. The coculture of the bare islets with the differentiated U937 cells stimulated proinflammatory cytokine (IL-1ß and TNF-α) secretion and caused islet death after 7 days, which simulated an early inflammatory response environment after islet transplantation. The PA-encapsulated islets, however, did not stimulate proinflammatory cytokine secretion and maintained islet viability up to 7 days. More insulin-producing ß cells were observed when islets were PA-encapsulated than control islets with the differentiated U937 cells for 7 days compared to the bare islets. This result was also confirmed by dithizone staining analysis. Further evaluation of islet functionality was assessed by a glucose-stimulated insulin secretion test. The PA-encapsulated islets showed greater insulin secretion response to glucose stimulation than the bare islets with the differentiated U937 cells after 3 and 7 days. These results demonstrated that islet encapsulation with the PA nanomatrix gel was able to improve islet survival and function in the presence of inflammatory responses, which will increase the success rate of islet engraftment and the efficacy of islet transplantation.

Progress and challenges of the bioartificial pancreas.

Pancreatic islet transplantation has been validated as a treatment for type 1 diabetes since it maintains consistent and sustained type 1 diabetes reversal. However, one of the major challenges in pancreatic islet transplantation is the body's natural immune response to the implanted islets. Immunosuppressive drug treatment is the most popular immunomodulatory approach for islet graft survival. However, administration of immunosuppressive drugs gives rise to negative side effects, and long-term effects are not clearly understood. A bioartificial pancreas is a therapeutic approach to enable pancreatic islet transplantation without or with minimal immune suppression. The bioartificial pancreas encapsulates the pancreatic islets in a semi-permeable environment which protects islets from the body's immune responses, while allowing the permeation of insulin, oxygen, nutrients, and waste. Many groups have developed various types of the bioartificial pancreas and tested their efficacy in animal models. However, the clinical application of the bioartificial pancreas still requires further investigation. In this review, we discuss several types of bioartificial pancreases and address their advantages and limitations. We also discuss recent advances in bioartificial pancreas applications with microfluidic or micropatterning technology.