Gastric environment-stable oral nanocarriers for in situ colorectal cancer therapy

Applications and advancements of polysaccharide-based nanostructures for enhanced drug delivery

Growing demand for highly effective, site-specific delivery of pharmaceuticals and nutraceuticals using nano-sized carriers has prompted increased scrutiny of carrier biocompatibility and biodegradability. To address these concerns, biodegradable natural polymers have emerged as a transformative domain, offering non-toxic, precisely targetable carriers capable of finely modulating cargo pharmacokinetics while generating innocuous decomposition by-products. This comprehensive review illuminates the emergence of polysaccharide-based nanoparticulate drug delivery systems. These systems establish an interactive interface between drug and targeted organs, guided by strategic modifications to polysaccharide backbones, which facilitate the creation of morphologically, constitutionally, and characteristically vibrant nanostructures through various fabrication routes, underpinning their pivotal role in biomedical applications. Advancements crucial to enhancing polysaccharide-based drug delivery, such as surface modifications and bioinspired modifications for enhanced targeting, and stimuli-responsive release, strategies to overcome biological barriers, enhance tumor penetration, and optimize therapeutic outcomes are highlighted. This review also examines some potent challenges, and the contemporary way out of them, and discusses future perspectives in the field.

How Nanoparticles Open the Paracellular Route of Biological Barriers: Mechanisms, Applications, and Prospects

Biological barriers are essential physiological protective systems and obstacles to drug delivery. Nanoparticles (NPs) can access the paracellular route of biological barriers, either causing adverse health impacts on humans or producing therapeutic opportunities. This Review introduces the structural and functional influences of NPs on the key components that govern the paracellular route, mainly tight junctions, adherens junctions, and cytoskeletons. Furthermore, we evaluate their interaction mechanisms and address the influencing factors that determine the ability of NPs to open the paracellular route, which provides a better knowledge of how NPs can open the paracellular route in a safer and more controllable way. Finally, we summarize limitations in the research models and methodologies of the existing research in the field and provide future research direction. This Review demonstrates the in-depth causes for the reversible opening or destruction of the integrity of barriers generated by NPs; more importantly, it contributes insights into the design of NP-based medications to boost paracellular drug delivery efficiency.

pH-Responsive Polymer Nanomaterials for Tumor Therapy

The complexity of the tumor microenvironment presents significant challenges to cancer therapy, while providing opportunities for targeted drug delivery. Using characteristic signals of the tumor microenvironment, various stimuli-responsive drug delivery systems can be constructed for targeted drug delivery to tumor sites. Among these, the pH is frequently utilized, owing to the pH of the tumor microenvironment being lower than that of blood and healthy tissues. pH-responsive polymer carriers can improve the efficiency of drug delivery in vivo, allow targeted drug delivery, and reduce adverse drug reactions, enabling multifunctional and personalized treatment. pH-responsive polymers have gained increasing interest due to their advantageous properties and potential for applicability in tumor therapy. In this review, recent advances in, and common applications of, pH-responsive polymer nanomaterials for drug delivery in cancer therapy are summarized, with a focus on the different types of pH-responsive polymers. Moreover, the challenges and future applications in this field are prospected.

Tunable Thermo-Responsive Properties of Hydroxybutyl Chitosan Oligosaccharide

In this study, a simple method was used to synthesize novel thermosensitive hydroxybutyl chitosan oligosaccharide (HBCOS) by introducing hydroxybutyl groups to C₆–OH of chitosan oligosaccharide (COS) chain. The variation in light scattering demonstrated that HBCOS had good thermosensitive properties and the particle size of HBCOS changed from 2.21–3.58 to 281.23–4,162.40 nm as the temperature increased to a critical temperature (LCST). The LCST of HBCOS (10 mg/ml) decreased from 56.25°C to 40.2°C as the degrees of substitution (DSs) increased from 2.96 to 4.66. The LCST of HBCOS with a DS of 4.66 decreased to 33.5°C and 30°C as the HBCOS and NaCl concentrations increased to 50 mg/ml and 4% (w/v), respectively. Variable-temperature FTIR spectroscopy confirmed that dehydration of hydrophobic chains and the transition of hydrogen bonds were the driving forces for the phase transition of HBCOS. Moreover, HBCOS was not cytotoxic at different concentrations. This work generated a novel thermosensitive HBCOS with tunable thermoresponsive properties and excellent biocompatibility, which may be a potential nanocarrier for the biomedical application.

Molecular intervention of colon cancer and inflammation manifestation by tannin capped biocompatible controlled sized gold nanoparticles from Terminalia bellirica: A green strategy for pharmacological drug formulation based on nanotechnology principles

Among the diverse nanomaterials, gold nanoparticles (AuNps) are utilised for various therapeutic application due to the distinct physical, chemical properties and biocompatibility. Synthesis of gold nanoparticles using plants is the promising route. This method is low cost, eco-friendly and higher biological activities. In this present study, Gold nanoparticles were synthesised from fruit extract of Terminalia bellirica fruit extract. Their anticancer and anti-inflammatory activity was evaluated against colorectal cancer cell line (HT29) and TNBS-induced zebrafish model. Highly stable tannin capped gold nanoparticles were synthesised from fruit extract broth of Terminalia bellirica rapidly. Structural and functional properties of the synthesised nanoparticles were studied by Fourier transform infrared spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM) equipped with energy-dispersive atomic X-ray spectroscopy (EDAX) and X-ray diffraction (XRD). All the characterisation studies reveal highly stable, crystalline, phytochemicals, mainly tannin doped, spherical, 28 nm controlled sized gold nanoparticles. The molecular mechanism of anticancer activity was studied by determining cancer markers' expression, which was studied using quantitative real-time polymerase chain reaction (qPCR). Antioxidative enzymes' status and apoptosis changes were also investigated. Synthesised nanoparticles brought a drastic reduction of all the tested cancer markers' expression. Notable changes in antioxidative enzymes' status and a good sign of apoptosis were observed in nanoparticles' treatment. The anti-inflammatory activity was studied against TNBS-induced zebrafish model, which was confirmed by determining inflammatory markers' expression TNF-α, iNOS (induced Nitric Oxide Synthase) and histopathological examination. Nanoparticles' treatment recorded a drastic reduction of inflammatory markers' expression. No marked sign of inflammation was also observed in histopathological analysis of the nanoparticles' treatment group. The present study suggests the possible utilisation of T. bellirica-mediated gold nanoparticles as an effective therapeutic agent against a prolonged inflammatory disease that progressively develops into cancer.

Orally Administrable Therapeutic Nanoparticles for the Treatment of Colorectal Cancer

Colorectal cancer (CRC) is one of the most common and lethal human malignancies worldwide; however, the therapeutic outcomes in the clinic still are unsatisfactory due to the lack of effective and safe therapeutic regimens. Orally administrable and CRC-targetable drug delivery is an attractive approach for CRC therapy as it improves the efficacy by local drug delivery and reduces systemic toxicity. Currently, chemotherapy remains the mainstay modality for CRC therapy; however, most of chemo drugs have low water solubility and are unstable in the gastrointestinal tract (GIT), poor intestinal permeability, and are susceptible to P-glycoprotein (P-gp) efflux, resulting in limited therapeutic outcomes. Orally administrable nanoformulations hold the great potential for improving the bioavailability of poorly permeable and poorly soluble therapeutics, but there are still limitations associated with these regimes. This review focuses on the barriers for oral drug delivery and various oral therapeutic nanoparticles for the management of CRC.

Thermoresponsive Chitosan/DOPA-Based Hydrogel as an Injectable Therapy Approach for Tissue-Adhesion and Hemostasis

Chitosan (CS) hydrogels are widely used in wound hemostatic agents due to their superior biocompatibility, biodegradability, and hemostatic effect. However, most of them fail to achieve great hemostatic effect because of poor adhesion to bleeding tissues. Also, the conventional implantation surgery of hemostatic hydrogels to internal bleeding wounds may cause secondary trauma to the human body. In this work, catechol-hydroxybutyl chitosan (HBCS-C) has been designed and prepared by grafting hydroxybutyl groups and catechol groups to the CS backbones. The multifunctional HBCS-C hydrogels are fabricated with the properties of thermosensitivity, injectability, tissue-adhesion, biodegradation, biocompatibility, and wound hemostasis. They exhibit excellent liquid-gel transition at different temperatures, through the changes of hydrophilic-hydrophobic interaction and hydrogen bonds generating from hydroxybutyl groups. By the multiple interactions between catechol groups/amino groups and tissues, the biocompatible hydrogels can strongly adhere on the surface of tissue. To further study, the bleeding rat-liver models are made to evaluate the hemostatic effects. After injecting the hydrogel precursor solution into the rat body, the hydrogels are not only formed in situ within 30 s but are also firmly adhered to the bleeding tissues which shows effective hemostasis. The injectability and tissue-adhesion improvement in this study gives a new insight into hemostatic agents, and the multifunctional hydrogels have a great potential in the biomedical application.