Yeast-inspired drug delivery: biotechnology meets bioengineering and synthetic biology.

INTRODUCTION: Yeast-based drug delivery offers a promising platform for the treatment of various medical conditions. Even the most promising nanoparticulate delivery systems have challenges from gastrointestinal barriers. The novel approach using bio-inspired yeast microcapsule helps in the delivery of charged nanoparticles like quantum dots, iron oxide nanoparticle, and various fluorescent nanoparticles. The long-term administration has a good safety profile compared to other delivery systems. Particles can be incorporated into yeast microcapsule by electrostatic interaction, layer-by-layer approach, and surface derivatization. AREAS COVERED: The article highlights the various applications of yeast cells in drug delivery. The authors describe the mechanism of encapsulation into yeast cells. The authors discuss various methods used for cell wall preparation and mechanisms associated with the passage of yeast cell through the gastrointestinal tract. The authors also review the association of biotechnology with bioengineering and synthetic biology approaches in transforming yeast as a delivery vehicle. EXPERT OPINION: Yeast provides an opportunity to use the principles of biotechnology and bioengineering to tune it to an efficient drug delivery carrier. The applications of yeast microcapsule for oral and topical administration are noteworthy. It is proved that yeast microcapsules prepared from yeast cells are promising drug delivery carriers.

Artificial Virus as Trump-card to Resolve Exigencies in Targeted Gene Delivery.

Viruses are potent pathogens that can effectively deliver the genetic material to susceptible host cells. This capability is beneficially utilized to successfully deliver the genetic material. However, the use of virus mediated gene delivery is considered divisive, because the potentially replicable genomes recombine or integrate with the cell DNA resulting in immunogenicity, ranging from inflammation to death. Thus, the need for potentially effective non-viral gene delivery vehicles arises. Non-viral vectors, protein only particles and virus like particles (VLP) can be constructed which contain all the necessary functional moieties. These resemble viruses and are called artificial or synthetic virus. The artificial virus eliminates the disadvantages of viral vectors but retain the beneficial effects of the viruses. Need for further functionalization can be avoided by this approach because incorporation of requisite agents such as cell ligands, membrane active peptides, etc. into proteins is possible. The protein- DNA complexes resemble bacterial inclusion bodies. Nucleic acids influence conformation of protein units which subsequently result in cell uptake and finally to the cell nucleus. Such tunable systems mimic the activities of infected viruses and are used for the safe and effective delivery of drugs and genetic material in gene therapy. The versatility, stability and biocompatible nature of artificial virus along with high transfection efficacy have made it favorite for gene delivery purposes, in addition to being useful for various biomedical and drug delivery applications.

Pharmaceutical product development: A quality by design approach.

The application of quality by design (QbD) in pharmaceutical product development is now a thrust area for the regulatory authorities and the pharmaceutical industry. International Conference on Harmonization and United States Food and Drug Administration (USFDA) emphasized the principles and applications of QbD in pharmaceutical development in their guidance for the industry. QbD attributes are addressed in question-based review, developed by USFDA for chemistry, manufacturing, and controls section of abbreviated new drug applications. QbD principles, when implemented, lead to a successful product development, subsequent prompt regulatory approval, reduce exhaustive validation burden, and significantly reduce post-approval changes. The key elements of QbD viz., target product quality profile, critical quality attributes, risk assessments, design space, control strategy, product lifecycle management, and continual improvement are discussed to understand the performance of dosage forms within design space. Design of experiments, risk assessment tools, and process analytical technology are also discussed for their role in QbD. This review underlines the importance of QbD in inculcating science-based approach in pharmaceutical product development.

Eugenol nanocapsule for enhanced therapeutic activity against periodontal infections.

Eugenol is a godsend to dental care due to its analgesic, local anesthetic, and anti-inflammatory and antibacterial effects. The aim of the present research work was to prepare, characterize and evaluate eugenol-loaded nanocapsules (NCs) against periodontal infections. Eugenol-loaded polycaprolactone (PCL) NCs were prepared by solvent displacement method. The nanometric size of the prepared NCs was confirmed by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The in vitro drug release was found to follow a biphasic pattern and followed Michaelis-Menten like model. The percentage cell viability values near to 100 in the cell viability assay indicated that the NCs are not cytotoxic. In the in vivo studies, the eugenol NC group displayed significant difference in the continuity of epithelium of the interdental papilla in comparison to the untreated, pure eugenol and placebo groups. The in vivo performance of the eugenol-loaded NCs using ligature-induced periodontitis model in rats indicated that eugenol-loaded NCs could prevent septal bone resorption in periodontitis. On the basis of our research findings it could be concluded that eugenol-loaded PCL NCs could serve as a novel colloidal drug delivery system for enhanced therapeutic activity of eugenol in the treatment of periodontal infections.

Eugenol significantly affects the flow of its nanodroplet gel.

INTRODUCTION: Development of novel biomaterials for drug delivery which forms a part of the so called novel drug delivery systems has always been exhilarating. Mechanical evaluation of polymer based topical gels, which would be subjected to load or stress during its application, is inevitable. METHODS: Rheological characterization was done by studying viscosity and yielding. Rheological modeling was also carried out. RESULTS: The viscosity and yield stress were inversely dependent on the eugenol concentration. The gels followed Herschel-Bulkley and Bingham rheological models. CONCLUSION: Nanodroplets are colloidal systems and the microstructural changes in the Carbopol based nanodroplet gels were unveiled using rheometry.

Novel gene delivery systems.

Gene therapy is an emerging field in medical and pharmaceutical sciences because of its potential in treating chronic diseases like cancer, viral infections, myocardial infarctions, and genetic disorders. Application of gene therapy is limited because of lack of suitable methods for proper introduction of genes into cells and therefore, this is an area of interest for most of the researchers. To achieve successful gene therapy, development of proper gene delivery systems could be one of the most important factors. Several nonviral and viral gene transfer methods have been developed. Even though the viral agents have a high transferring efficiency, they are difficult to handle due to their toxicity. To overcome the safety problems of the viral counterpart, several nonviral in vitro and in vivo gene delivery systems are developed. Out of these, the most promising and latest systems include polymer-based nonviral gene carriers, dendrimers, and physical means like electroporation, microinjection, etc., Shunning of possible immunogenicity and toxicity, and the feasibility of repeated administration are some of the merits of nonviral gene delivery systems over viral gene delivery. An ideal nonviral gene carrying system should possess all these merits without any compromise to its gene transferring efficiency. The viral gene delivery systems include lytic and nonlytic vectors for drug delivery. Inspite of its toxicity they are still preferred because of their long term expression, stability, and integrity. This review explores the recent developments and relevancy of the novel gene delivery systems in gene therapy.

Exploring oral nanoemulsions for bioavailability enhancement of poorly water-soluble drugs.

INTRODUCTION: More than 40% of new chemical entities discovered are poorly water soluble and suffer from low oral bioavailability. In recent years, nanoemulsions are receiving increasing attention as a tool of delivering these low-bioavailable moieties in an efficient manner. AREAS COVERED: This review gives a brief description about how oral nanoemulsions act as a tool to improve the bioavailability of poorly water-soluble drugs. The recurrent confusion found in the literature regarding the theory behind the formation of nanoemulsions is clarified, along with the difference between nanoemulsion and lyotropic 'microemulsion' phase. This paper gives a clear-cut idea about all possible methods for the preparation of nanoemulsions and the advantages and disadvantages of each method are described. A description of the stability problems of nanoemulsions and their prevention methods is also provided, in addition to a comprehensive update on the patents and research works done in the arena of oral nanoemulsions. EXPERT OPINION: Low-energy emulsification techniques can also produce stable nanoemulsions. It is guaranteed that oral nanoemulsions can act as a potential tool for the delivery of poorly water-soluble therapeutic moieties in a very efficient manner.

Eugenol: a natural compound with versatile pharmacological actions.

Eugenol, the major constituent of clove oil, has been widely used for its anesthetic and analgesic action in dentistry. Eugenol exhibits pharmacological effects on almost all systems and our aim is to review the research work that has identified these pharmacological actions. Eugenol possesses significant antioxidant, anti-inflammatory and cardiovascular properties, in addition to analgesic and local anesthetic activity. The metabolism and pharmacokinetics of the compound in humans have been studied. Eugenol has also been used as a penetration enhancer. The compound is a very promising candidate for versatile applications, and the design of new drugs based on the pharmacological effects of eugenol could be beneficial.