Effects of alkylated-chitosan-DNA nanoparticles on the function of macrophages

Synthesis and Characterization of PEGylated and Fluorinated Chitosans: Application to the Synthesis of Targeted Nanoparticles for Drug Delivery

To synthesize chitosan nanoparticles (CS NPs), ionic gelation is a very attractive method. It relies on the spontaneous supramolecular assembly of cationic CS with anionic compounds, which leads to nanohydrogels. To extend ionic gelation to functionalized CS, the assessment of CS degree of substitution (DS_CS) is a key step. In this paper, we have developed a hyphenated strategy for functionalized CS characterization, based upon ¹H, DOSY and, when relevant, 1D diffusion-filtered ¹⁹F NMR spectroscopies. For that, we have synthesized two series of water-soluble CS via amidation of CS amino groups with mPEG₂₀₀₀-COOH or fluorinated synthons (TFB-COOH). The aforementioned NMR techniques helped to discriminate between ungrafted and grafted synthons and finally to determine DS_CS. According to DS_CS values, the selection of CS-mPEG₂₀₀₀ or CS-TFB copolymers can be made to obtain, in the presence of hyaluronic acid (HA) and tripolyphosphate (TPP), CS-mPEG₂₀₀₀-TPP/HA or CS-TFB-TPP/HA nanohydrogels suitable for drug delivery.

A surface modification of clozapine-loaded nanocapsules improves their efficacy: A study of formulation development and biological assessment

This work aimed to develop nanocapsules (NC) coated with polysorbate 80 (P80), cationic chitosan (CS) or polyethylene glycol (PEG) using clozapine (CZP) as the drug model. The zeta potential, pH and encapsulation efficiency were directly affected by the CS coating. Using the bag dialysis method, the in vitro CZP release from CS-coated nanocapsules was similar to the PEG-coated at pH 7.4. Nanocapsules coated with PEG and CS exhibited an increased action duration compared to the P80-coated nanocapsules in pseudo-psychosis induced by d,l-amphetamine in rats. When comparing both groups, the group administered CS-coated nanocapsules showed better activity than the PEG-coated nanocapsules at 6, 10 and 12h after d,l-amphetamine administration. The pharmacokinetic assessment in rats demonstrated that the observed half-lives were free CZP<P80-coated<PEG-coated ̴ CS-coated nanocapsules. Both the P80- and PEG-coated nanocapsules showed a statistically significant increase in their volume of distribution compared to free CZP. On the other hand, the cationic nanocapsules showed a decrease in total clearance. Together, these results indicate that the PEG and CS coatings are a promising delivery system for CZP in the treatment of schizophrenia.

Biocompatibility of chitosan carriers with application in drug delivery

Chitosan is one of the most used polysaccharides in the design of drug delivery strategies for administration of either biomacromolecules or low molecular weight drugs. For these purposes, it is frequently used as matrix forming material in both nano and micron-sized particles. In addition to its interesting physicochemical and biopharmaceutical properties, which include high mucoadhesion and a great capacity to produce drug delivery systems, ensuring the biocompatibility of the drug delivery vehicles is a highly relevant issue. Nevertheless, this subject is not addressed as frequently as desired and even though the application of chitosan carriers has been widely explored, the demonstration of systems biocompatibility is still in its infancy. In this review, addressing the biocompatibility of chitosan carriers with application in drug delivery is discussed and the methods used in vitro and in vivo, exploring the effect of different variables, are described. We further provide a discussion on the pros and cons of used methodologies, as well as on the difficulties arising from the absence of standardization of procedures.

Opsonization, biodistribution, cellular uptake and apoptosis study of PEGylated PBCA nanoparticle as potential drug delivery carrier

PURPOSE

For nanocarrier-based targeted delivery systems, preventing phagocytosis for prolong circulation half life is a crucial task. PEGylated poly(n-butylcyano acrylate) (PBCA) NP has proven a promising approach for drug delivery, but an easy and reliable method of PEGylation of PBCA has faced a major bottleneck.

METHODS

PEGylated PBCA NPs containing docetaxel (DTX) by modified anionic polymerization reaction in aqueous acidic media containing amine functional PEG were made as an single step PEGylation method. In vitro colloidal stability studies using salt aggregation method and antiopsonization property of prepared NPs using mouse macrophage cell line RAW264 were performed. In vitro performance of anticancer activity of prepared formulations was checked on MCF7 cell line. NPs were radiolabeled with 99mTc and intravenously administered to study blood clearance and biodistribution in mice model.

RESULTS

These formulations very effectively prevented phagocytosis and found excellent carrier for drug delivery purpose. In vivo studies display long circulation half life of PBCA-PEG20 NP in comparison to other formulations tested.

CONCLUSIONS

The PEGylated PBCA formulation can work as a novel tool for drug delivery which can prevent RES uptake and prolong circulation half life.