Biomaterials Based on Essential Fatty Acids and Carbohydrates for Chronic Wounds.

Chronic wounds such as decubitus ulcer remain challenging due to their integrated and overlapping phases. The matrix metalloproteinases (MMPs) enzymes, whose main function is to degrade all kinds of extracellular matrix (ECM) proteins, aid cellular migration and extracellular remodeling. MMPs, in the wound bed, allow the lysis of the dead tissues, by which the macrophages task becomes easier to digest the dead cells. MMPs activities should be monitored and inhibited as the healing process proceeds. If MMPs are not inhibited in time, they will break down tissue to attack the ECM itself creating chronic wounds. In the current work, conjugated linoleic acid (CLA) and ricinoleic acid (RA) are extracted from commercial oils as MMPs inhibitors. A pharmaceutical carrier is formulated containing chitosan fine particles, impregnated silver nanoparticles into microcrystalline cellulose, CLA and RA. Carrier and the active ingredients were prepared and characterized by spectral and morphological analysis. The final formulation was examined for antimicrobial, cytotoxicity, and in-vivo wound healing activity. Results showed a strong inhibitory activity against the tested pathogenic microorganisms for the silver contacting samples. The rates of wound closures during wound healing in diabetic male-rats of formulas containing ricinoleic acid was faster than that containing conjugated linoleic acid.

Screening of natural products for therapeutic activity against solid tumors.

Most of the currently used cancer therapeutics are natural products. These agents were generally discovered based on their toxicity to tumour cells using various bioassays. Although the exact mechanisms of action of the most commonly used cancer therapeutics such as anthracyclins, podophyllotoxins and camptothecin are incompletely understood, it is becoming increasingly clear that these agents often show complex modes of action at the cellular level, interacting with numerous targets. Such complex modes of action may be the very reason for clinical efficacy. For discovering new cytotoxic anticancer drugs sophisticated screening methods were used. The principles of such screening projects conducted, using collections of purified natural products or extracts from plants have been described. By performing simple but robust pre-screening tests such as the brine shrimp assay, bioactive extracts can be identified. Extracts (65) prepared from a collection of Egyptian plants were identified that showed cytotoxity on HepG2 cells. Interestingly, 22 (33%) of these raw extracts, induced > 2-fold induction of caspase-cleavage activity in a colon carcinoma cell line, consistent with induction of apoptosis. Only a fraction of the diversity of the biosphere has been tested for biological activity and novel cancer therapeutics remains to be discovered.