N-octyl-O-sulfate chitosan-modified liposomes for delivery of docetaxel: preparation, characterization, and pharmacokinetics

Chitosan films and scaffolds for regenerative medicine applications: A review

Over the last years, chitosan has demonstrated unparalleled characteristics for regenerative medicine applications. Beside excellent antimicrobial and wound healing properties, this polysaccharide biopolymer offers favorable characteristics such as biocompatibility, biodegradability, and film and fiber-forming capabilities. Having plentiful active amine groups, chitosan can be also readily modified to provide auxiliary features for growing demands in regenerative medicine, which is constantly confronted with new problems, necessitating the creation of biocompatible, immunogenic and biodegradable film/scaffold composites. A new look at the chitosan composites structure/activity/application tradeoff is the primary focus of the current review, which can help researchers to detect the bottlenecks and overcome the shortcomings that arose from this intersection. In the current review, the most recent advances in chitosan films and scaffolds in terms of preparation techniques and modifying methods for improving their functional properties, in three major biomedical fields i.e., tissue engineering, wound healing, and drug delivery are surveyed and discussed.

Different influence of sulfated chitosan with different sulfonic acid group sites on HUVECs behaviors

The vascularization within the scaffold is still a significant challenge in tissue engineering applications. Sulfated chitosan (SCS) as an amazing substance have been used in tissue engineering to stimulate angiogenesis. However, it is not clear whether they have difference in the ability to promote vascularization of SCS with different sulfonic acid group sites. The aim of this study was to evaluate human umbilical vein endothelial cells (HUVECs) viability and differentiation in vitro, affected by three types of sulfated chitosan' i.e. 2-N-6-O-sulfated chitosan (2,6-SCS), 3'6-O-sulfated chitosan (3,6-SCS) and 6-O-sulfated chitosan (6-SCS). The results are showed that all the SCS possesses excellent biological properties to promote HUVECs viability and proliferation. Especially, 2,6-SCS promotes desirable intracellular nitric oxide secretion and capillary tube formation. Meanwhile, 2,6-SCS up-regulate the related gene and protein expression compared with other sulfonic acid group sites SCS and heparin. Therefore, 2,6-SCS is a promising substitute material for angiogenesis and as aqueous formulation can be employed to fabrication functionalization scaffold surface with promoted angiogenesis.

Novel pH-triggered biocompatible polymeric micelles based on heparin-α-tocopherol conjugate for intracellular delivery of docetaxel in breast cancer

In this study, pH-triggered polymeric micelle comprising α-tocopherol (TOC) and heparin (HEP) was developed and loaded with docetaxel (DTX). The amphiphilic copolymer was synthesized by grafting TOC onto HEP backbone by a pH-cleavable bond. DTX-loaded micelles were characterized in terms of critical micelle concentration (CMC), particle size, zeta potential, entrapment efficiency (EE), pH-responsive behavior, and drug release. In vitro cytotoxicity of the micelles against breast cancer cells was investigated by MTT assay. The cellular uptake of coumarin-loaded micelles was also evaluated. Furthermore, the pharmacokinetics of DTX-loaded micelles was evaluated and compared with that of Taxotere^®.HEP-CA-TOC copolymers showed low CMC values and high EE. At pH 7.4, the micelles remained stable in size and shape, whereas considerable changes in particle size and morphology were observed at pH 5.5. DTX-loaded micelles showed pH-dependent drug release profiles. Coumarin-loaded micelles showed higher cellular uptake than free coumarin. Therefore, the DTX-loaded micelles showed more toxicity against breast cancer cells than free DTX. A significant increase in T_1/2 β, AUC_0-∞ and MRT was observed in DTX-loaded micelle treated group as compared to the group treated with Taxotere^®.The results suggest that the pH-sensitive HEP-modified micelles could be promising for enhanced intracellular drug delivery of DTX for cancer treatment.

Progress in the Development of Chitosan-Based Biomaterials for Tissue Engineering and Regenerative Medicine

Over the last few decades, chitosan has become a good candidate for tissue engineering applications. Derived from chitin, chitosan is a unique natural polysaccharide with outstanding properties in line with excellent biodegradability, biocompatibility, and antimicrobial activity. Due to the presence of free amine groups in its backbone chain, chitosan could be further chemically modified to possess additional functional properties useful for the development of different biomaterials in regenerative medicine. In the current review, we will highlight the progress made in the development of chitosan-containing bioscaffolds, such as gels, sponges, films, and fibers, and their possible applications in tissue repair and regeneration, as well as the use of chitosan as a component for drug delivery applications.

Applications of cellulose and chitin/chitosan derivatives and composites as antibacterial materials: current state and perspectives

The bacterial infections have always a serious problem to public health. Scientists are developing new antibacterial materials to overcome this problem. Polysaccharides are promising biopolymers due to their diverse biological functions, low toxicity, and high biodegradability. Chitin and chitosan have antibacterial properties due to their cationic nature, while cellulose/bacterial cellulose does not possess any antibacterial activity. Moreover, the insolubility of chitin in common solvents, the poor solubility of chitosan in water, and the low mechanical properties of chitosan have restricted their biomedical applications. In order to solve these problems, chemical modifications such as quaternization, carboxymethylation, cationization, or surface modification of these polymers with different antimicrobial agents, including metal and metal oxide nanoparticles, are carried out to obtain new materials with improved physiochemical and biological properties. This mini review describes the recent progress in such derivatives and composites with potential antibacterial applications.

Enhanced antitumor effect on intrapulmonary tumors of docetaxel lung-targeted liposomes in a rabbit model of VX2 orthotopic lung cancer

Allergic reactions and severe systemic toxicity are two major challenges for the clinical application of docetaxel (DTX) for treatment of non-small-cell lung cancer (NSCLC). We developed a novel lung-targeted DTX-loaded liposome (DTX-LP), an efficient drug delivery system, with a patented DBaumNC technology to overcome these deficiencies. In the present study, we describe the targeting activity, tumor inhibition rate (TIR), survival, pathology, tumor apoptosis and metabolism of DTX after intravenous injection of DTX-LP compared to the DTX injection (DTX-IN) formulation based on the VX2 orthotopic lung cancer rabbit model. Biodistribution studies revealed the highest accumulation in lung and tumor within 12 h after the injection of DTX-LP. The increased TIR indicates that the growth of tumor was slowed. Pathology tests demonstrated that DTX-LP can reduce metastasis and toxicity to non-targeted organs, leading to greatly extended survival time and improved survival of tumor-bearing rabbits. Flow cytometry and immunohistochemistry confirmed that DTX-LP is highly efficacious in tumor tissue, leading to a significant increase of tumor apoptosis and decrease of proliferation and angiogenesis. The results from this study demonstrate the increased intrapulmonary tumor targeting activity, enhanced antitumor effect and reduced toxicity of DTX-LP compared to DTX-IN and highlight its clinical prospects for NSCLC therapy.

Co-delivery of docetaxel and curcumin prodrug via dual-targeted nanoparticles with synergistic antitumor activity against prostate cancer

PURPOSE

Combination therapy is increasingly used as a primary cancer treatment regimen. In this report, we designed EGFR peptide decorated nanoparticles (NPs) to co-deliver docetaxel (DTX) and pH sensitive curcumin (CUR) prodrug for the treatment of prostate cancer.

RESULTS

EGFR peptide (GE11) targeted, pH sensitive, DTX and CUR prodrug NPs (GE11-DTX-CUR NPs) had an average diameter of 167nm and a zeta potential of -37.5mV. The particle size of the NPs was adequately maintained in serum and a sustained drug release pattern was observed. Improved inhibition of cancer cell and tumor tissue growth was shown in the GE11-DTX-CUR NPs group compared to the other groups.

CONCLUSION

It can be summarized that DTX and CUR prodrug could be delivered into tumor cells simultaneously by the GE 11 targeting and the EPR effect of NPs. The resulting GE11-DTX-CUR NPs is a promising system for the synergistic antitumor treatment of prostate cancer.

Cabazitaxel-loaded human serum albumin nanoparticles as a therapeutic agent against prostate cancer

Cabazitaxel-loaded human serum albumin nanoparticles (Cbz-NPs) were synthesized to overcome vehicle-related toxicity of current clinical formulation of the drug based on Tween-80 (Cbz-Tween). A salting-out method was used for NP synthesis that avoids the use of chlorinated organic solvent and is simpler compared to the methods based on emulsion-solvent evaporation. Cbz-NPs had a narrow particle size distribution, suitable drug loading content (4.9%), and superior blood biocompatibility based on in vitro hemolysis assay. Blood circulation, tumor uptake, and antitumor activity of Cbz-NPs were assessed in prostatic cancer xenograft-bearing nude mice. Cbz-NPs exhibited prolonged blood circulation and greater accumulation of Cbz in tumors along with reduced toxicity compared to Cbz-Tween. Moreover, hematoxylin and eosin histopathological staining of organs revealed consistent results. The levels of blood urea nitrogen and serum creatinine in drug-treated mice showed that Cbz-NPs were less toxic than Cbz-Tween to the kidneys. In conclusion, Cbz-NPs provide a promising therapeutic for prostate cancer.

Nanoways to overcome docetaxel resistance in prostate cancer

Prostate cancer is the most common non-cutaneous malignancy in American men. Docetaxel is a useful chemotherapeutic agent for prostate cancer that has been available for over a decade, but the length of the treatment and systemic side effects hamper compliance. Additionally, docetaxel resistance invariably emerges, leading to disease relapse. Docetaxel resistance is either intrinsic or acquired by adopting various mechanisms that are highly associated with genetic alterations, decreased influx and increased efflux of drugs. Several combination therapies and small P-glycoprotein inhibitors have been proposed to improve the therapeutic potential of docetaxel in prostate cancer. Novel therapeutic strategies that may allow reversal of docetaxel resistance include alterations of enzymes, improving drug uptake and enhancement of apoptosis. In this review, we provide the most current docetaxel reversal approaches utilizing nanotechnology. Nanotechnology mediated docetaxel delivery is superior to existing therapeutic strategies and a more effective method to induce P-glycoprotein inhibition, enhance cellular uptake, maintain sustained drug release, and improve bioavailability.

Improved physical and in vitro digestion stability of a polyelectrolyte delivery system based on layer-by-layer self-assembly alginate-chitosan-coated nanoliposomes

To improve lipid membrane stability and prevent leakage of encapsulated food ingredients, a polyelectrolyte delivery system (PDS) based on sodium alginate (AL) and chitosan (CH) coated on the surface of nanoliposomes (NLs) has been prepared and optimized using a layer-by-layer self-assembly deposition technique. Morphology and FTIR observation confirmed PDS has been successfully coated by polymers. Physical stability studies (pH and heat treatment) indicated that the outer-layer polymers could protect the core (NLs) from damage, and PDS showed more intact structure than NLs. Further enzymic digestion stability studies (particle size, surface charge, free fatty acid, and model functional component release) demonstrated that PDS could better resist lipolytic degradation and facilitate a lower level of encapsulated component release in simulated gastrointestinal conditions. This work suggested that deposition of polyelectrolyte on the surface of NLs can stabilize liposomal structure, and PDS could be developed as a formulation for delivering functional food ingredients in the gastrointestinal tract.

Self-assembled methoxy poly(ethylene glycol)-cholesterol micelles for hydrophobic drug delivery

To promote the application of methoxy poly(ethylene glycol)-cholesterol (mPEG-Chol), mPEG-Chol was used to prepare core-shell micelles encapsulating poorly water-soluble docetaxel (DTX-PM) by modified cosolvent evaporation method. Approaches to enhance DTX entrapment efficiency (EE) and minimize particle size were investigated in detail, including organic and aqueous phase composition, organic/aqueous phase ratio, and polymer concentration. In optimal formulation, micelles had higher EE (97.6%) and drug loading (4.76%) with the diameter of 13.76 ± 0.68 nm and polydispersity index of 0.213 ± 0.006. Transmission electron microscopy (TEM) showed that the micelles were spherical, and differential scanning calorimetry (DSC) analysis proved that DTX was successfully entrapped into mPEG-Chol micelles. The in vitro cytotoxicity experiments displayed that blank micelles had no effect on the growth of SKOV-3, BXPC-3, A549, and HepG-2 cells, demonstrating that mPEG-Chol was one of the biocompatible biomaterials. The half inhibition concentration of DTX-PM on SKOV-3, BXPC-3, A549, and HepG-2 cells were 10.08, 7.6, 28.37, and 125.75 ng/mL, respectively. DTX-PM had the similar antitumor activity to free DTX, indicating that mPEG-Chol was a promising micellar vector for hydrophobic drug delivery. In addition, this work provided a new and facile approach to prepare drug-loaded micelles with controllable performances.