Surface engineering of liposomes for stealth behavior

The potential of liposomes with carbonic anhydrase IX to deliver anticancer ingredients to cancer cells in vivo

Drug delivery nanocarriers, especially targeted drug delivery by liposomes are emerging as a class of therapeutics for cancer. Early research results suggest that liposomal therapeutics enhanced efficacy, while simultaneously reducing side effects, owing to properties such as more targeted localization in tumors and active cellular uptake. Here, we highlight the features of immunoliposomes that distinguish them from previous anticancer therapies, and describe how these features provide the potential for therapeutic effects that are not achievable with other modalities. While a large number of studies has been published, the emphasis here is placed on the carbonic anhydrase IX (CA-IX) and the conjugated liposomes that are likely to open a new chapter on drug delivery system by using immunoliposomes to deliver anticancer ingredients to cancer cells in vivo.

Therapeutic strategies to combat antibiotic resistance

With multidrug resistant bacteria on the rise, new antibiotic approaches are required. Although a number of new small molecule antibiotics are currently in the development pipeline with many more in preclinical development, the clinical options and practices for infection control must be expanded. Biologics and non-antibiotic adjuvants offer this opportunity for expansion. Nevertheless, to avoid known mechanisms of resistance, intelligent combination approaches for multiple simultaneous and complimentary therapies must be designed. Combination approaches should extend beyond biologically active molecules to include smart controlled delivery strategies. Infection control must integrate antimicrobial stewardship, new antibiotic molecules, biologics, and delivery strategies into effective combination therapies designed to 1) fight the infection, 2) avoid resistance, and 3) protect the natural microbiome. This review explores these developing strategies in the context of circumventing current mechanisms of resistance.

EpCAM-targeted liposomal si-RNA delivery for treatment of epithelial cancer

BACKGROUND

RNA interference (RNAi) technology using short interfering RNA (si-RNA) has shown immense potential in the treatment of cancers through silencing of specific genes. Cationic non-viral vectors employed for gene delivery exhibit toxic effects in normal cells limiting their widespread use, therefore, site-specific delivery using benign carriers could address this issue.

OBJECTIVE

Design of a non-toxic carrier that enables site-specific delivery of si-RNA into the cancer cells is of prime importance to realize the promise of gene silencing.

METHODS

In the present study, non-cationic liposomes encapsulating si-RNA against epithelial cell adhesion molecule (EpCAM) were developed and characterized for encapsulation efficiency, colloidal stability, in vitro and in vivo gene silencing efficacy.

RESULTS

PEGylated liposomes containing phosphatidyl choline and phosphatidyl ethanolamine exhibited maximum si-RNA encapsulation efficiency of 47%, zeta potential of -21 mV, phase transition temperature of 51 °C and good colloidal stability in phosphate-buffered saline (PBS) containing bovine serum albumin (BSA) and plasma protein (PP) at 37 °C. Conjugation of epithelial cell adhesion molecule (EpCAM) antibody to the liposomes resulted in enhanced cell internalization and superior down-regulation of EpCAM gene in MCF-7 cell lines when compared with free si-RNA and the non-targeted liposomes. In vivo evaluation of immunoliposomes for their efficacy in regressing the tumor volume in Balb/c SCID mice showed about 35% reduction of tumor volume in comparison with the positive control when administered with an extremely low dose of 0.15 mg/kg twice a week for 4 weeks.

CONCLUSION

Our results exhibit that the nanocarrier-mediated silencing of EpCAM gene is a promising strategy to treat epithelial cancers.

Inhalable PEGylated Phospholipid Nanocarriers and PEGylated Therapeutics for Respiratory Delivery as Aerosolized Colloidal Dispersions and Dry Powder Inhalers

Nanomedicine is making groundbreaking achievements in drug delivery. The versatility of nanoparticles has given rise to its use in respiratory delivery that includes inhalation aerosol delivery by the nasal route and the pulmonary route. Due to the unique features of the respiratory route, research in exploring the respiratory route for delivery of poorly absorbed and systemically unstable drugs has been increasing. The respiratory route has been successfully used for the delivery of macromolecules like proteins, peptides, and vaccines, and continues to be examined for use with small molecules, DNA, siRNA, and gene therapy. Phospholipid nanocarriers are an attractive drug delivery system for inhalation aerosol delivery in particular. Protecting these phospholipid nanocarriers from pulmonary immune system attack by surface modification by polyethylene glycol (PEG)ylation, enhancing mucopenetration by PEGylation, and sustaining drug release for controlled drug delivery are some of the advantages of PEGylated liposomal and proliposomal inhalation aerosol delivery. This review discusses the advantages of using PEGylated phospholipid nanocarriers and PEGylated therapeutics for respiratory delivery through the nasal and pulmonary routes as inhalation aerosols.

Liposomal delivery and polyethylene glycol-liposomal oxaliplatin for the treatment of colorectal cancer (Review)

Oxaliplatin is effective for the treatment of advanced colorectal cancer; however, its application is restricted due to its dose-limiting toxicity. Liposomes are sphere-shaped vesicles consisting of one or more phospholipid bilayers. Liposomes as drug carriers are characterized by delayed release, lesion targeting and may be used as a drug-delivery system to decrease the side effects of cytotoxic drugs. Active targeting modification of liposomes may change the biological distribution of the anticancer agents, reduce or reverse multidrug resistance of tumor cells and enhance the effects of anticancer therapy. Based on the characteristics mentioned above, the aim of the present review was to demonstrate that polyethylene glycol-liposomes containing oxaliplatin may offer advantages for the treatment of colorectal cancer in clinical practice.