A carbohydrate mimetic peptide modified size-shrinkable micelle nanocluster for anti-tumor targeting and penetrating drug delivery

Polysaccharide-based nanocarriers for efficient transvascular drug delivery

Polysaccharide-based nanocarriers (PBNs) are the focus of extensive investigation because of their biocompatibility, low cost, wide availability, and chemical versatility, which allow a wide range of anticancer agents to be loaded within the nanocarriers. Similar to other nanocarriers, most PBNs are designed to extravasate out of tumor vessels, depending on the enhanced permeability and retention (EPR) effect. However, the EPR effect is compromised in some tumors due to the heterogeneity of tumor structures. Transvascular transport efficacy is decreased by complex blood vessels and condensed tumor stroma. The limited extravasation impedes efficient drug delivery into tumor parenchyma, and thus affects the subsequent tumor accumulation, which hinders the therapeutic effect of PBNs. Therefore, overcoming the biological barriers that restrict extravasation from tumor vessels is of great importance in PBN design. Many strategies have been developed to enhance the EPR effect that involve nanocarrier property regulation and tumor structure remodeling. Moreover, some researchers have proposed active transcytosis pathways that are complementary to the paracellular EPR effect to increase the transvascular extravasation efficiency of PBNs. In this review, we summarize the recent advances in the design of PBNs with enhanced transvascular transport to enable optimization of PBNs in the extravasation of the drug delivery process. We also discuss the obstacles and challenges that need to be addressed to clarify the transendothemial mechanism of PBNs and the potential interactions between extravasation and other drug delivery steps.

Carbohydrate anchored lipid nanoparticles

Nanotechnology has been a dynamic field for formulation scientists with multidisciplinary research being conducted worldwide. Advancements in development of functional nanosystems have led to evolution of breakthrough technologies. Lipidic nanosystems, in particular, are highly preferred owing to their non-immunogenic safety profiles along with a range of versatile intrinsic properties. Surface modification of lipid nanoparticles by anchoring carbohydrates to these systems is one such attractive drug delivery technology. Carbohydrates confer interesting properties to the nanosystems such as stealth, biostability, bioavailability, reduced toxicity due to decreased immunogenic response, targeting potential as well as ease of commercial availability. The carbohydrate anchored systems can be developed using methods such as adsorption, incorporation (nanoprecipitation or solvent displacement method), crosslinking and grafting. Current review provides a detailed overview of potential lipid based nanoparticulate systems with an emphasis on liposomes, solid lipid nanoparticles, nanostructures lipid carriers and micelles. Review further explores basics of surface modification, methods applied therein, advantages of carbohydrates as surface modifiers, their versatile applications, techniques for characterization of carbohydrate anchored systems and vital regulatory aspects concerned with these specialized systems.

A Nanosized Codelivery System Based on Intracellular Stimuli-Triggered Dual-Drug Release for Multilevel Chemotherapy Amplification in Drug-Resistant Breast Cancer

Lacking nano-systems for precisely codelivering the chemotherapeutics paclitaxel (PTX) and the natural P-glycoprotein (P-gp) inhibitor, quercetin (QU), into cancer cells and controlling their intracellular release extremely decreased the anticancer effects in multidrug resistant (MDR) tumors. To overcome this hurdle, we constructed hybrid polymeric nanoparticles (PNPs) which consist of redox-sensitive PTX/polyethyleneimine-tocopherol hydrogen succinate-dithioglycollic acid PNPs and pH-sensitive hyaluronic acid-QU conjugates. The obtained hybrid PNPs can be internalized into drug-resistant breast cancer cells by the hyaluronic acid/CD44-mediated endocytosis pathway and escape from the lysosome through the “proton sponge effect”. Under the trigger of intracellular stimuli, the nanoplatform used the pH/glutathione dual-sensitive disassembly to release QU and PTX. The PTX diffused into microtubules to induce tumor cell apoptosis, while QU promoted PTX retention by down-regulating P-gp expression. Moreover, tocopherol hydrogen succinate and QU disturbed mitochondrial functions by generating excessive reactive oxygen species, decreasing the mitochondrial membrane potential, and releasing cytochrome c into the cytosol which consequently achieved intracellular multilevel chemotherapy amplification in MDR cancers. Importantly, the PNPs substantially suppressed tumors growth with an average volume 2.54-fold lower than that of the control group in the MCF-7/ADR tumor-bearing nude mice model. These presented PNPs would provide a valuable reference for the coadministration of natural compounds and anticarcinogens for satisfactory combination therapy in MDR cancers.

Calcium hydroxide/iodoform nanoparticles as an intracanal filling medication: synthesis, characterization, and in vitro study using a bovine primary tooth model

The aims of this in vitro study were to synthesize, characterize, and evaluate the efficacy of a Calcium Hydroxide/Iodoform nanoparticles (CHIN) paste compared with Ultrapex as intracanal filling medication using an experimental model of bovine primary teeth. CH nanoparticle synthesis was performed via the simple hydrolysis technique of reacting calcium nitrate with sodium hydroxide. SEM-EDS and FT-IR analyses were used to characterize the obtained product. 30% of CH nanoparticles were combined with 40% of iodoform and 30% silicone oil to prepare an intracanal filling paste (CHIN). All endodontic procedures were performed on 34 uniradicular primary bovine teeth. Every root canal was instrumented with K files (up to #35) and obturated with the nanoparticle paste (experimental) or Ultrapex^® (control). Three outcome variables were studied: penetration depth through the root dentinal tubules, Ca²⁺ ion release, and filling paste dissolution rate. The obtained data were analyzed by Student's t test. The X-ray diffraction pattern of CH nanoparticles showed characteristic peaks at CH, as confirmed by FT-IR analyses in which an intense signal was observed at 3643 cm^-1, characteristic of CH. In the morphological characterization, CH particles could be detected at the nanosize scale. When applied as intracanal filling, the CHIN paste exhibited a higher level of penetration through the root dentin tubules. The global mean penetration measures were 500 µm for the experimental paste and 380 µm for the control paste (p < 0.05). The release of Ca²⁺ ions (up to the seventh day) and the dissolution rate were significantly higher in the experimental paste group than in the control group. No significant differences were observed between the groups regarding pH levels. The findings of this study suggest the potential suitability of CHI nanoparticles as an alternative intracanal filling medication for infected or devitalized primary teeth.

Construction of a novel "ball-and-rod" MSNs-pp-PEG system: a promising antitumor drug delivery system with a particle size switchable function

To utilize the advantages of drug carriers of different sizes, a size switchable "ball-and-rod" drug delivery system was constructed, which could switch its size in response to enzymes in tumors. It would be a promising system with long circulation and deep penetration properties, which enable its application in tumor treatment.

Potential drug delivery nanosystems for improving tumor penetration

Nanosystems, as one of the most important drug delivery systems, play a crucial rule in tumor therapy. However, the deep tumor penetration is retarded by the tumor physiological factors and nanomedicine properties. In this review, we firstly elaborate the factors which impact tumor penetration, including the tumor physiological factors and nanomedicine properties. Then, the latest and potential drug delivery nanosystems for improving tumor penetration are summarized and analyzed in detail. Moreover, recent combination therapies for improving penetration are described to enhance penetration. Finally, we summarize the typical clinical therapies of potential drug delivery nanosystems.