Rust diseases continue to cause significant losses to wheat production worldwide. Although the life of effective race-specific resistance genes can be prolonged by using gene combinations, an alternative approach is to deploy varieties that posses adult plant resistance (APR) based on combinations of minor, slow rusting genes. When present alone, APR genes do not confer adequate resistance especially under high disease pressure; however, combinations of 4-5 such genes usually result in ''near-immunity'' or a high level of resistance. Although high diversity for APR occurs for all three rusts in improved germplasm, relatively few genes are characterized in detail. Breeding for APR to leaf rust and stripe rust in CIMMYT spring wheats was initiated in the early 1970s by crossing slow rusting parents that lacked effective race-specific resistance genes to prevalent pathogen populations and selecting plants in segregating populations under high disease pressure in field nurseries. Consequently most of the wheat germplasm distributed worldwide now possesses near-immunity or adequate levels of resistance. Some semidwarf wheats such as Kingbird, Pavon 76, Kiritati and Parula show high levels of APR to stem rust race Ug99 and its derivatives based on the Sr2-complex, or a combination of Sr2 with other uncharacterized slow rusting genes. These parents are being utilized in our crossing program and a Mexico-Kenya shuttle breeding scheme is used for selecting resistance to Ug99. High frequencies of lines with near-immunity to moderate levels of resistance are now emerging from these activities. After further yield trials and quality assessments these lines will be distributed internationally through the CIMMYT nursery system.

Injury or damage to tissue and organs is a major health problem, resulting in about half of the world's annual healthcare expenditure every year. Advances in the fields of stem cells (SCs) and biomaterials processing have provided a tremendous leap for researchers to manipulate the dynamics between these two, and obtain a skin substitute that can completely heal the wounded areas. Although wound healing needs a coordinated interplay between cells, extracellular proteins and growth factors, the most important players in this process are the endogenous SCs, which activate the repair cascade by recruiting cells from different sites. Extra cellular matrix (ECM) proteins are activated by these SCs, which in turn aid in cellular migrations and finally secretion of growth factors that can seal and heal the wounds. The interaction between ECM proteins and SCs helps the skin to sustain the rigors of everyday activity, and in an attempt to attain this level of functionality in artificial three-dimensional (3D) constructs, tissue engineered biomaterials are fabricated using more advanced techniques such as bioprinting and laser assisted printing of the organs. This review provides a concise summary of the most recent advances that have been made in the area of polymer bio-fabrication using 3D bio printing used for encapsulating stem cells for skin regeneration. The focus of this review is to describe, in detail, the role of 3D architecture and arrangement of cells within this system that can heal wounds and aid in skin regeneration.

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Terminalia chebula is one of the traditional medicines used in the treatment of many diseases. In the present work, different concentrations of various organic and aqueous extracts (solvent-free) of T. chebula were tested on fibroblast (L929) and keratinocytes cells to evaluate its biocompatible concentration by using MTT and live-dead viability/cytotoxic assay. These extracts were found to be effective in decreasing the ammonia accumulation in the media, thereby reducing its toxic effect on cells. DPPH assay further confirmed the free-radical scavenging ability of the extracts which increased with the increase in concentration of each extract. Cell proliferation/apoptosis, cytoskeletal structure, and ECM production were further evaluated by live-dead assay and phalloidin/cytokeratin staining, respectively. The cytoskeletal structure and ECM secretion of the cells treated with extracts showed higher cellular activity in comparison to control. In conclusion, we have demonstrated the effect of these extracts of T. chebula on both types of skin cells and optimized concentration in which it could be used as a bioactive component for wound healing applications by increasing cell proliferation and decreasing free-radical production without affecting the normal cellular matrix. It can also find applications in other therapeutics applications where ammonia toxicity is a limiting factor.