Food preservation using biopreservative agents mainly microbial based metabolites have gained more attention in the modern food sector due to their broad spectrum anti-microbial efficacy with high biocompatibility. However, the effectiveness of these biopreservatives is highly dependent on suitable formulation which will enhance the desired efficacy without affecting the nutritional value of the foods. Polylysine-actinomycete derived anti-microbial metabolite is used as biopreservative agent in various food products. This review provides a valuable insight into the formulation of polylysine with nanotechnology principles for enhanced antimicrobial efficacy against food spoilage organisms. This review highlighted the diverse methods of polylysine nanoformulation preparation. Formulation of polylysine as functionalised nanomaterials can be prepared via green science or green technology principles was extensively studied in this review. This study also revealed the methods for the determination of anti-microbial assays and biocompatibility tests in vitro and in vivo biocompatibility tests. Future prospects of nanoformulated polylysine in bio preservation can be extended to safe processing of canned and ready-to-eat food products without affecting the nutritional value of the foods.

Bacterial vaginosis (BV) is the most common vaginal infection affecting women of childbearing age, and is associated with a substantial burden on women\'s physical, emotional, sexual and social lives, as well as being linked to a number of gynaecological and obstetrical complications and adverse pregnancy outcomes. Antibiotics, such as metronidazole or clindamycin, are recommended as first-line treatment for BV, but may be associated with antibiotic resistance, high rates of recurrence and poor patient treatment satisfaction. Astodrimer sodium gel is a novel, non-antibiotic treatment for BV that is not systemically absorbed. It prevents pathogenic bacteria from adhering to the vaginal wall, and disrupts and inhibits the formation of pathogenic bacterial biofilms. Clinical cure rates of 50-57% were observed in patients with BV treated with astodrimer sodium compared with 17-21% treated with placebo (p < 0.001) in Phase 3 trials. In a separate Phase 3 trial, recurrence of BV occurred in 44% of patients treated with astodrimer sodium compared with 54% of patients who received placebo (p = 0.015). Astodrimer sodium is well tolerated, with vulvovaginal candidosis being the only treatment-related adverse event reported to occur more often than with placebo. The availability of astodrimer sodium, a well-tolerated, convenient, non-antibiotic treatment for BV, represents significant progress in the treatment of this burdensome condition.

Epsilon-poly-L-lysine (epsilon-PL) is a natural biomaterial that is biodegradable, edible and non-toxic toward humans and the environment. Based on the research history of epsilon-PL, we reviewed the biosynthesis, degradation and the metabolic pathway of epsilon-PL. We also addressed the status of epsilon-PL research in China.

Epsilon-Poly-L-lysine (epsilon-PL) is a polymer with strong antimicrobial activity and consists of 25-35 L-lysine monomers linked via epsilon-amino-alpha-carboxyl peptide bond. This polymer is one of only two homo-poly (amino acid) polymers known in nature. To date, the biosynthesis mechanism of epsilon-PL was remained unclear. Recently, epsilon-PL synthetase was identified as a nonribosomal peptide synthetase and it utilized L-lysine to synthesize epsilon-PLs of various chain length by iteratively condensing reaction, which was similar to type I polyketide synthase and was not determined by epsilon-PL-degrading enzyme. Meanwhile, the shutter vectors pLAE001 and pLAE003, special for epsilon-PL producer have been constructed, which is significant for studying epsilon-PL biosynthesis. In this review, the biosynthesis of epsilon-PL and the genetic transformation were introduced. Also, the study in our group was presented and the views related to e-PL study were raised. Finally, the prospect of application of combinational biosynthesis in epsilon-PL-producing strain improvement was also discussed considering epsilon-PL synthetase is a nonribosomal peptide synthetase containing several modules.

Cystic fibrosis is a disease for which a number of Phase I clinical trials of gene therapy have been initiated. Several factors account for the high level of interest in a gene therapy approach to this disease. CF is the most common lethal inherited disease in Caucasian populations. The lung, the organ that is predominantly responsible for the morbidity and mortality in CF patients, is accessible by a non-invasive method, the inhalation of aerosols. The vectors employed in the Phase I trials have included recombinant adenoviruses, adeno-associated viruses and cationic lipids. While there have been some positive results, the success of the vectors until now has been limited by either immunogenicity or low efficiency. A more fundamental obstacle has been the absence of appropriate receptors on the apical surface of airway epithelial cells. Molecular conjugates with carbohydrate substitution to provide targeting offer several potential advantages. Lactosylated polylysine in which 40% of the lysines have been substituted with lactose has been shown to provide a high efficiency of transfection in primary cultures of CF airway epithelial cells. Other important features include a relatively low immunogenicity and cytotoxicity. Most importantly, the lactosylated polylysine was demonstrated to give nuclear localization in CF airway epithelial cells. Until now, most non-viral vectors did not have the capability to provide nuclear localization. These unique qualities provided by the lactosylation of non-viral vectors, such as polylysine may help to advance the development of molecular conjugates sufficiently to warrant their use in future clinical trials for the gene therapy of inherited diseases of the lung.

A technique for microencapsulation of bovine spermatozoa has been developed with minimal spermatozoal injury and thus of potential use in artificial insemination. The polymers poly-l-lysine, polyvinylamine and protamine sulfate have proven best for membranes. Encapsulation has been successful with capsules ranging in size from 0.75 to 1.5 mm, and with sperm concentrations from 45 to 180 x 10(6) cells mL-1. Successful extenders include CUE, CAPROGEN, and egg yolk-citrate-glycerol (maximum 10% v/v egg yolk for normal capsular shape). Capsule fragility (ability to rupture under ageing and physical stress) is negatively related to membrane thickness which ranges from 1.92 to 5.32 microns (depending on the concentration of polymer used) and positively related to concentration of sperm encapsulated. Heterospermic studies have shown that encapsulated sperm are capable of fertilization in vivo, but are at a disadvantage to unencapsulated sperm when cows are inseminated at conventional times. Uterine retention of inseminates is favoured by capsules having a \'sticky\' membrane. Using current procedures, preliminary homospermic fertility studies indicate that sperm encapsulated with poly-l-lysine or protamine sulfate may achieve normal fertility.

The original report on the microencapsulation of islets of Langerhans used sodium alginate and poly-L-lysine (PLL) to form the capsules. Although several alternative materials have subsequently been used with vary-mg degrees of success, it is those studies using islets encapsulated in alginate-PLL-alginate which are reviewed in detail in this article. Since the first report of islet microencapsulation, many studies have demonstrated excellent in vitro viability of encapsulated islets. However, transplantation experiments into chemically induced diabetic recipients have yielded varied results, with some studies showing good long-term graft function whilst in others grafts failed due to pericapsular fibrosis. The use of naturally occurring animal models of type 1 (insulin-dependent) diabetes has demonstrated a decline in graft function, suggesting that this presents a more complex problem to be solved than that in chemically induced diabetic recipients. Fibrosis of capsules has been the major problem causing graft failure, and this has been demonstrated to be more severe in spontaneously diabetic models. However, recent advances in alginate purification and attempts to reduce the size of the encapsulated islets are major steps towards encapsulated islet transplants becoming a viable proposition for the treatment of type 1 diabetic patients.