CRISPR/Cas9 Genome Editing for Tissue-Specific In Vivo Targeting: Nanomaterials and Translational Perspective.

Clustered randomly interspaced short palindromic repeats (CRISPRs) and its associated endonuclease protein, i.e., Cas9, have been discovered as an immune system in bacteria and archaea; nevertheless, they are now being adopted as mainstream biotechnological/molecular scissors that can modulate ample genetic and nongenetic diseases via insertion/deletion, epigenome editing, messenger RNA editing, CRISPR interference, etc. Many Food and Drug Administration-approved and ongoing clinical trials on CRISPR adopt ex vivo strategies, wherein the gene editing is performed ex vivo, followed by reimplantation to the patients. However, the in vivo delivery of the CRISPR components is still under preclinical surveillance. This review has summarized the nonviral nanodelivery strategies for gene editing using CRISPR/Cas9 and its recent advancements, strategic points of view, challenges, and future aspects for tissue-specific in vivo delivery of CRISPR/Cas9 components using nanomaterials.

Liposome-encapsulated fish oil protein-tagged gold nanoparticles for intra-articular therapy in osteoarthritis.

AIM: To provide multilayered combination therapies encompassing nanoparticles and organic peptides and to assess their efficacy in the treatment of arthritis. MATERIALS & METHODS: Fish oil protein (FP) was isolated from fish oil glands and tagged with spherical gold nanoparticles (GNPs). Tagged GNPs were encapsulated in DPPC liposomes (FP-GNP-DPPC) and characterized. RESULTS & CONCLUSION: FP increased the hydrophilicity of GNP, while encapsulation of FP-GNP within liposomes increased the hydrophobicity. In vitro release studies of FP-GNP-DPPC exhibited sustained release of FP in simulated synovial fluid. FP-GNP-DPPC injected into intra-articular joints of rats displayed anti-osteoarthritic effects in osteoarthritic rat model. This is the first study to report the anti-osteoarthritic activity of FP and DPPC encapsulated FP-GNP liposomes.

Polyethylene glycol (PEG): a versatile polymer for pharmaceutical applications.

INTRODUCTION: Polyethylene glycol (PEG) is a polymer of choice in drug delivery systems. This USFDA-approved polymer is popular due to its tunable properties and well-established safety profile: prime requisites considered during the selection of any excipient in formulation development. AREAS COVERED: The unique properties and applications of PEG have been discussed at length in the existing literature. However, a proper guidance on selection of PEG grade to cater to one's purpose is lacking. This article provides preliminary guidelines to formulators on selection of appropriate PEG grade, typically based on its physico-chemical properties and role-based functional application in pharmaceuticals. It should be noted that the aim article is not to deep dive in each application area. EXPERT OPINION: Guidance on PEG application and grade of choice is lacking in the available literature. The authors have discussed and provided guidance to formulators on the appropriate PEG grade selection for particular application based on the available in vitro and in vivo literature data. In this review a State-of-the-art use of PEG in therapeutic applications, its clinical status and commercial use is also summarized. Nevertheless, toxicities related to different PEG grades and related impurities are discussed in this review.

Bioenhanced oral curcumin nanoparticles: Role of carbohydrates.

The paper discusses polysaccharide-adsorbed curcumin-Gantrez nanoparticles for bioenhancement of oral curcumin. Nanoparticles revealed no change in size over time in pH 1.2 and 7.4, and a rapid drug release in pH 1.2 and 7.4 medium containing surfactant. Without adsorbed polysaccharides, nanoparticles exhibited high Cmax (61.3 ± 22.3 ng/mL), sustained plasma concentration up to 24h and 117% absolute bioavailability, attributed to bioadhesion. In contrast galactose polysaccharides arabinogalactan and kappa-carrageenan adsorbed nanoparticles exhibited rapid absorption with higher Cmax of 109.5 ± 31.2 ng/mL and 92.3 ± 21.2 ng/mL, respectively, but faster elimination and absolute bioavailability of greater than 25%. The glucose polysaccharide pullulan adsorbed nanoparticles exhibited significantly lower Cmax (39.7 ± 20.6 ng/mL) and bioavailability (13%). Lower bioavailability of polysaccharide adsorbed nanoparticles was attributed to high metabolism of curcumin in the intestine as a result of faster gastric elimination and high intestinal localization. However polysaccharide-adsorbed nanoparticles could play an important role in bioenhancement of drugs specifically those exhibiting good stability across the gastrointestinal tract.

In situ polyethylene sebacate particulate carriers as an alternative to Freund's adjuvant for delivery of a contraceptive peptide vaccine--A feasibility study.

The present study evaluates the feasibility of particulate carriers of a biodegradable polymer polyethylene sebacate (PES) as an alternative to Freund's adjuvant in the design of a peptide vaccine formulation. The vaccine formulation comprised of PES and the antigen KLH conjugated 80kDa HSA peptide-1 dissolved in N-methyl-2-pyrrolidone (NMP)/NMP-water as solvent. The antigen revealed good stability and the formulations were readily syringeable. Intradermal injection of the formulations resulted in the formation of PES particulates in situ at the site of injection. The NMP formulations revealed larger particulates which elicited no immunogenic response when injected in rabbits. On the other hand the NMP-water formulation revealed formation of microparticles which were significantly smaller in size, in combination with a small fraction of nanoparticles. It elicited an antibody titer up to 1:3200 in rabbits following intradermal injection. Western blot confirmed generation of antibodies specific to the peptide. Contraceptive efficacy was confirmed by loss of sperm motility and head-to-head agglutination of sperms in the treatment group. Unlike the severe reactions observed with administration of Freund's adjuvant, only mild hypersensitivity reaction was observed with the PES formulations. The mild reaction coupled with the contraceptive efficacy observed suggested PES particulates as a viable alternative to Freund's adjuvant.

Asialoglycoprotein receptor mediated hepatocyte targeting - strategies and applications.

Hepatocyte resident afflictions continue to affect the human population unabated. The asialoglycoprotein receptor (ASGPR) is primarily expressed on hepatocytes and minimally on extra-hepatic cells. This makes it specifically attractive for receptor-mediated drug delivery with minimum concerns of toxicity. ASGPR facilitates internalization by clathrin-mediated endocytosis and exhibits high affinity for carbohydrates specifically galactose, N-acetylgalactosamine and glucose. Isomeric forms of sugar, galactose density and branching, spatial geometry and galactose linkages are key factors influencing ligand-receptor binding. Popular ligands for ASGPR mediated targeting are carbohydrate polymers, arabinogalactan and pullulan. Other ligands include galactose-bearing glycoproteins, glycopeptides and galactose modified polymers and lipids. Drug-ligand conjugates provide a viable strategy; nevertheless ligand-anchored nanocarriers provide an attractive option for ASGPR targeted delivery and are widely explored. The present review details various ligands and nanocarriers exploited for ASGPR mediated delivery of drugs to hepatocytes. Nanocarrier properties affecting ASGPR mediated uptake are discussed at length. The review also highlights the clinical relevance of ASGPR mediated targeting and applications in diagnostics. ASGPR mediated hepatocyte targeting provides great promise for improved therapy of hepatic afflictions.

Comparative in silico-in vivo evaluation of ASGP-R ligands for hepatic targeting of curcumin Gantrez nanoparticles.

The present study aims to design hepatic targeted curcumin (CUR) nanoparticles using Gantrez (GZ) as a polymer. Three carbohydrate-based hepatocyte asialoglycoprotein receptor (ASGP-R) ligands were selected for the study, namely kappa carrageenan (KC), arabinogalactan (AG), and pullulan (P). AG and KC are galactose based while P is a glucose-based polymer. CUR-GZ nanoparticles were prepared by nanoprecipitation and anchored with the ligands by nonspecific adsorption onto preformed nanoparticles. The change in zeta potential values confirmed adsorption of the ligands. Docking simulation was evaluated as a tool to predict ligand ASGP-R interactions, using grid-based ligand docking with energies (Glide). Monomers and dimers were used as representative units of polymer for docking analysis. The binding of ASGP-R was validated using D-galactose as monomer. The interaction of the ligands with the receptor was evaluated based on Glide scores and E model values, both for monomers and dimers. The data of the docking study based on Glide scores and E model values suggested higher affinity of AG and P to the ASGP-R, compared to KC. At 1 h, following intravenous administration of the nanoparticles to rats, the in vivo hepatic accumulation in the order CUR-GZAG > CUR-GZKC > CUR-GZP correlated with the docking data based on Glide scores. However, at the end of 6 h, pullulan exhibited maximum hepatic accumulation and arabinogalactan minimum accumulation (p < 0.05). Nevertheless, as predicted by docking analysis, arabinogalactan and pullulan revealed maximum hepatic accumulation. Docking analysis using dimers as representative stereochemical units of polymers provides a good indication of ligand receptor affinity. Docking analysis provides a useful tool for the preliminary screening of ligands for hepatic targeting.

Inorganic nanovectors for nucleic acid delivery.

Nucleic acids show immense potential to treat cancer, acquired immune deficiency syndrome, neurological diseases and other incurable human diseases. Upon systemic administration, they encounter a series of barriers and hence barely reach the site of action, the cell. Intracellular delivery of nucleic acids is facilitated by nanovectors, both viral and non-viral. A major advantage of non-viral vectors over viral vectors is safety. Nanovectors evaluated specifically for nucleic acid delivery include polyplexes, lipoplexes and other cationic carrier-based vectors. However, more recently there is an increased interest in inorganic nanovectors for nucleic acid delivery. Nevertheless, there is no comprehensive review on the subject. The present review would cover in detail specific properties and types of inorganic nanovectors, their preparation techniques and various biomedical applications as therapeutics, diagnostics and theranostics. Future prospects are also suggested.