Fabrication and characterization of chitosan–collagen crosslinked membranes for corneal tissue engineering

This article describes a chitosan–collagen composite membrane as corneal tissue-engineering biomaterials. The membrane was prepared by dissolving the chitosan into collagen with the weight ratio of 0, 15, 30, 45, 60, and 100%, followed by crosslinked with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide. Mechanical properties, contact angles, and optical transmittance were determined and compared between chitosan membrane and crosslinking composite membrane. As a result, the optical transparency and mechanical strength of the chitosan–collagen membranes were significantly better than that of the sample of chitosan. In addition, in vitro cell culture studies revealed that the collagen has no negative effect on the cell morphology, viability, and proliferation and possess good biocompatibility. Overall, the dendrimer crosslinked chitosan–collagen composite membranes showed promising properties that suggest that these might be suitable biomaterials for corneal tissue-engineering applications.     

Chlorophyll derivatives can be an efficient weapon in the fight against dengue

Dengue, a mosquito-borne viral infection, is one of the major public health concerns in the tropical and subtropical regions of the world. Approximately, 2.5 billion people across the world are at risk from dengue and 50 to 100 million new infections of dengue occur annually. There is yet no vaccine or medicine available against dengue, and treatment remains only supportive. Targeting its vector by a combination of biological and chemical approaches and management of breeding sites are currently the only existing approaches to control or eliminate dengue. Chlorophyll derivatives like chlorophyllin and pheophorbide have been reported as effective natural photosensitizers against larvae of several insects including flies. Chlorophyll derivatives were also reported effective against larval stages of freshwater snails as well as against certain parasites of fish. This article briefly discusses the possible application of chlorophyll derivatives in controlling dengue vectors and hence the disease itself. Chlorophyll derivatives can prove to be a good contributor in an integrated approach against dengue.     

肠道微生态与人体疾病相关性研究现状

人类肠道有超过百万亿种微生物,其中包括1000余种已知细菌,这些细菌对肠道微生态具有至关重要的作用。根据已知的微生物与体循环的关系,目前广大学者普遍认为肠道微生态的改变与多种疾病的发生有直接联系。通过总结肠道微生态失衡引发的相关性疾病,引起人们重视,并通过挖掘微生态新靶点,达到缓解、治愈相关疾病的目的。