Chitosan is a natural polycationic linear polysaccharide derived from chitin. The low solubility of chitosan in neutral and alkaline solution limits its application. Nevertheless, chemical modification into composites or hydrogels brings to it new functional properties for different applications. Chitosans are recognized as versatile biomaterials because of their non-toxicity, low allergenicity, biocompatibility and biodegradability. This review presents the recent research, trends and prospects in chitosan. Some special pharmaceutical and biomedical applications are also highlighted.

China is encountering formidable healthcare challenges brought about by the problem of aging. By 2050, there will be 400 million Chinese citizens aged 65+, 150 million of whom will be 80+. The undesirable consequences of the one-child policy, rural-to-urban migration, and expansion of the population of ‘empty nest ’ elders are eroding the traditional family care of the elders, further exacerbating the burden borne by the current public healthcare system. The challenges of geriatric care demand prompt attention by proposing strategies for improvement in several key areas. Major diseases of the elderly that need more attention include chronic non-communicable diseases and mental health disorders. We suggest the establishment of a home care-dominated geriatric care system, and a proactive role for researchers on aging in reforming geriatric care through policy dialogs. We propose ideas for preparation of the impending aging burden and the creation of a nurturing environment conducive to healthy aging in China.

Genomic DNA from 32 unrelated families with male-limited precocious puberty was examined for the previously described Asp-578 --Gly,

In the testicular cancer cell line, NT2, we previously demonstrated that differentially methylated regions were located in introns or intergenic regions, and postulated these might regulate non-coding RNAs. Three micro-RNAs and three small nucleolar RNAs were differentially methylated; one, miR-199a, was associated with the progression and prognosis of gastric and ovarian cancers. In this report we document, by epigenomic profiling of testicular tissue, that miR-199a is transcribed as antisense of dynamin 3 (chromosome 1q24.3), and hypermethylation of this region is correlated with miR-199a-5p/3p repression and tumor malignancy. Re-expression of miR-199a in testicular cancer cells led to suppression of cell growth, cancer migration, invasion and metastasis. The miR-199a-5p, one of two mature miRNA species derived from miR-199a, is associated with tumor malignancy. We further identified the embryonal carcinoma antigen podocalyxin-like protein 1 (PODXL), an anti-adhesive protein expressed in aggressive tumors, as a target of miR-199a-5p. We demonstrated PODXL is overexpressed in malignant testicular tumor, and cellular depletion of PODXL resulted in suppression of cancer invasion. The inverse relationship between PODXL and miR-199a-5p expression suggests PODXL is a downstream effector mediating the action of miR199a-5p. This report identifies DNA methylation, miR-199a dysregulation and PODXL as critical factors in tumor malignancy.