Sensitive complex micelles based on host-guest recognition from chitosan-graft-β-cyclodextrin for drug release

Cyclodextrin-Based Polymeric Drug Delivery Systems for Cancer Therapy

Cyclodextrins (CDs) are one of the most extensively studied cyclic-oligosaccharides due to their low toxicity, good biodegradability and biocompatibility, facile chemical modification, and unique inclusion capacity. However, problems such as poor pharmacokinetics, plasma membrane disruption, hemolytic effects and a lack of target specificity still exist for their applications as drug carriers. Recently, polymers have been introduced into CDs to combine the advantages of both biomaterials for the superior delivery of anticancer agents in cancer treatment. In this review, we summarize four types of CD-based polymeric carriers for the delivery of chemotherapeutics or gene agents for cancer therapy. These CD-based polymers were classified based on their structural properties. Most of the CD-based polymers were amphiphilic with the introduction of hydrophobic/hydrophilic segments and were able to form nanoassemblies. Anticancer drugs could be included in the cavity of CDs, encapsulated in the nanoparticles or conjugated on the CD-based polymers. In addition, the unique structures of CDs enable the functionalization of targeting agents and stimuli-responsive materials to realize the targeting and precise release of anticancer agents. In summary, CD-based polymers are attractive carriers for anticancer agents.

Cyclodextrin-Based Arsenal for Anti-Cancer Treatments

Anti-cancer drugs are mostly limited in their use due to poor physicochemical and biopharmaceutical properties. Their lower solubility is the most common hurdle limiting their use upto their potential. In the recent years, the cyclodextrin (CD) complexation have emerged as existing approach to overcome the problem of poor solubility. CD-based nano-technological approaches are safe, stable and showed well in vivo tolerance and greater payload for encapsulation of hydrophobic drugs for the targeted delivery. They are generally chosen due to their ability to get self-assembled to form liposomes, nanoparticles, micelles and nano-sponges etc. This review paper describes a birds-eye view of the various CD-based nano-technological approaches applied for the delivery of anti-cancer moieties to the desired target such as CD based liposomes, niosomes, niosoponges, micelles, nanoparticles, monoclonal antibody, magnetic nanoparticles, small interfering RNA, nanorods, miscellaneous formulation of anti-cancer drugs containing CD. Moreover, the author also summarizes the various shortcomings of such a system and their way ahead.

Chitosan coated fluorescent mesoporous silica for the sensitive and selective detection of H2O2

A novel turn-on fluorescent sensor for hydrogen peroxide (H₂O₂) was prepared from chitosan (CS) coating mesoporous silica nanoparticles (MSNs) loaded with 1-(4-Aminophenyl)-1,2,2-triphenylethene (TPE-NH₂) and silver nanoparticles (AgNCs). The surface of MSNs was coated by CS as the gatekeeper and the template for loading of AgNCs. Because of the surface plasmon-enhanced energy transfer (SPEET), AgNCs effectively quenched the fluorescence emission of nanoparticles. In the presence of H₂O₂, AgNCs can be oxidized to Ag⁺, resulting in the recovery of fluorescence. This fluorescent sensor was characterized with respect to its chemical composition, morphological features and optical properties by means of FTIR, XRD, TGA, SEM, TEM, XPS, UV-Vis and fluorescence spectroscopy. The MSN/TPE-CS@Ag nanoparticles showed good sensitivity and selectivity for H₂O₂ even with various interfering ions and agents. Under optimized conditions, the detection limit for H₂O₂ was 0.64 μM in the rage of 1-300 μM. The feasibility of the practical application of this probe was confirmed by accurate quantitative of H₂O₂ in practical samples.

Preparation and Release of pH-Sensitive β-Cyclodextrin Derivative Micelles Loaded with Paclitaxel

In this paper, a new amphiphilic mono-6-β-cyclodextrin octadecylimine (6-β-CD-N-ODMA) copolymer was synthesized based on β-cyclodextrin and octadecylamine, which can self-assemble to form polymeric micelles. Drug-loaded micelles (a new drug carrier) were obtained using 6-β-CD-N-ODMA and paclitaxel (PTX) by the dialysis method. Orthogonal experiments were used to optimize the preparation method of the drug-loaded micelles. The drug-loading content of the carrier prepared by the optimized method was 1.97%. The physicochemical properties of blank micelles and drug-loaded micelles were evaluated by the fluorescence probe method, infrared spectra, dynamic light scattering, and scanning electron microscopy. The release properties of the carrier were investigated. The carrier has good pH sensitivity and the cumulative release rate after 96 h was 88% in PBS (pH = 5.0). The Ritger–Peppas equation is the optimal model for PTX released at pH 5.0, implying that the hydrolysis effect of 6-β-CD-N-ODMA is the main reason for PTX release. The results indicate that the developed carrier can increase the solubility of PTX and possess potential for increased clinical efficacy of PTX.

Facile Preparation of β-Cyclodextrin-grafted Chitosan Electrospun Nanofibrous Scaffolds as a Hydrophobic Drug Delivery Vehicle for Tissue Engineering Applications

Despite advances in the bio-tissue engineering area, the technical basis to directly load hydrophobic drugs on chitosan (CTS) electrospun nanofibers (ENs) has not yet been fully established. In this study, we fabricated CTS ENs by using an electrospinning (ELSP) system, followed by surface modification using succinyl-beta-cyclodextrin (β-CD) under mild conditions. The β-CD-modified CTS (βCTS) ENs had slightly increased hydrophobicity compared to pristine CTS ENs as well as decreased residual amine content on the surface. Through FTIR spectroscopy and thermogravimetric analysis (TGA), we characterized the surface treatment physiochemically. In the drug release test, we demonstrated the stable and sustained release of a hydrophobic drug (e.g., dexamethasone) loaded on β-CD ENs. During in vitro biocompatibility assessments, the grafting of β-CD was shown to not reduce cell viability compared to pristine CTS ENs. Additionally, cells proliferated well on β-CD ENs, and this was confirmed by F-actin fluorescence staining. Overall, the material and strategies developed in this study have the potential to load a wide array of hydrophobic drugs. This could be applied as a drug carrier for a broad range of tissue engineering applications.

Long-term treatment of polysaccharides-based hydrogel microparticles as oral insulin delivery in streptozotocin-induced type 2 diabetic mice

To develop a more effective and safer drug for the treatment of type 2 diabetes mellitus (T2DM), polysaccharides-based hydrogel microparticles as oral insulin delivery was prepared and explored. This study was aimed to evaluate the antidiabetic effects and hypoglycemic mechanism with long-term administration(four weeks) of oral insulin hydrogel microparticles in type 2 diabetic mice on a model of diabetes using a high fat diet combined with streptozotocin. The results revealed that the long-term treatment of oral insulin polysaccharides-based hydrogel microparticles could significantly alleviate the symptoms of polyphagia, polydipsia, polyuria and weight loss in diabetic mice. Also, oral administration of insulin hydrogel microparticles could significantly reduce fasting blood glucose levels, ameliorate insulin resistance and increase insulin sensitivity in the mice with T2DM. The concentration of plasma TG, TC, LDL-C, FFA, BUN, CRE significantly decreased and the levels of HDL-C increased showed that insulin polysaccharides-based hydrogel microparticles were effective in regulating lipid metabolism and prevent diabetic nephropathy complication in diabetic mice. In addition, the supplementation of insulin hydrogel microparticles could significant improve the antioxidant capacity by increasing the level of SOD, CAT and decreasing the level of MDA, GPT, NO, TNF-α, and reverse histological deterioration of kidney and pancreas in diabetic mice. The above outcome concluded that insulin polysaccharides-based hydrogel microparticles may exhibit promising anti-diabetic activity and the potential to be a drug candidate for T2DM.

Smart stimuli-responsive drug delivery systems based on cyclodextrin: A review

Stimulated by researches in materials chemistry and medicine fields, drug delivery has entered a new stage of development. Drug delivery systems have been extensively studied according to the differences in the drug therapeutic environment such as pH, light, temperature, magnet, redox, enzymes, etc. Cyclodextrin is a smart tool that has been proven to be used in the preparation of drug delivery, and has become a new area of concern in recent years. In this review, we discuss recent research advances in smart stimuli-responsive cyclodextrin-based drug delivery. First, different stimuli-responsive drug delivery systems based on cyclodextrin are introduced and classified. Then, the characteristics of different types of stimuli-responsive drug delivery systems are described, and their applications are emphasized. Finally, current challenges and future development opportunities of smart stimuli-responsive drug delivery systems based on cyclodextrin are discussed.