Thermo-sensitive hydrogel-mediated locally sequential release of doxorubicin and palbociclib for chemo-immunotherapy of osteosarcoma

Injectable Hydrogel Technologies for Bone Disease Treatment

Injectable hydrogels represent a highly promising approach for localized drug delivery systems (DDSs) in the management of bone-related conditions such as osteoporosis, osteonecrosis, osteoarthritis, osteomyelitis, and osteosarcoma. Their appeal lies in their biocompatibility, adjustable mechanical properties, and capacity to respond to external stimuli, including pH, temperature, light, redox potential, ionic strength, and enzymatic activity. These features enable enhanced targeted delivery of bioactive agents. This mini-review evaluates the synthesis of injectable hydrogels as well as recent advancements for treating a range of bone disorders, focusing on their mechanisms as localized and sustained DDSs for delivering drugs, nanoparticles, growth factors, and cells (e.g., stem cells). Moreover, it highlights their clinical studies for bone disease treatment. Additionally, it emphasizes the potential synergy between injectable hydrogels and hydrogel-based point-of-care technologies, which are anticipated to play a pivotal role in the future of bone disease therapies. Injectable hydrogels have the potential to transform bone disease treatment by facilitating precise, sustained, and minimally invasive therapeutic delivery. Nevertheless, significant challenges, including long-term biocompatibility, scalability, reproducibility, and precise regulation of drug release kinetics, must be addressed to unlock their clinical potential fully. Addressing these challenges will not only advance bone disease therapy but also open new avenues in regenerative medicine and personalized healthcare.

Self-assembled injectable Icariin@ Ti3C2Tx/doxorubicin hydrogel preserving osteogenesis while synergizing photodynamic and chemodynamic therapy for osteosarcoma

Local therapy involving injectable hydrogel systems loaded with doxorubicin (DOX) has garnered significant attention in the realm of osteosarcoma (OS) research. Nevertheless, it has been noted that the local delivery of high-dose DOX exerts a pronounced inhibitory impact on osteogenesis, which is detrimental to the restoration of functional capabilities after OS treatment. To address this challenge, we have designed a self-assembled injectable hydrogel system that integrates photodynamic and chemodynamic therapy, aiming to enhance efficacy while mitigating adverse effects on osteogenic differentiation. In this study, an injectable sodium alginate (SA) hydrogel was fabricated by encapsulating titanium carbide powder (Ti3C2Tx) and osteoprotegerin Icariin (ICA) along with DOX. This hydrogel system demonstrated remarkable drug-loading capacity and sustained drug release. Furthermore, under near-infrared (NIR) irradiation, the hydrogel displayed outstanding photothermal effects, which, in conjunction with chemotherapy and phototherapy, effectively eradicated UMR-106 tumor cells in vitro. The incorporation of ICA not only enhanced the anti-tumor effect but also alleviated the adverse effects of DOX on the osteogenic differentiation inhibition of bone marrow mesenchymal stem cells (BMSCs). In vivo, findings further confirmed that injectable ITD/SA hydrogels can synergistically heighten anti-osteosarcoma effectiveness while mitigating local osteogenic toxicity. Given these benefits, this hydrogel holds extensive application prospects in the local therapy of OS.

Multi-drug sequential release systems: Construction and application for synergistic tumor treatment

In tumor treatment, the sequence and timing of drug action have a large influence on therapeutic efficacy. Multi-drug sequential release systems (MDSRS) enable the sequential and/or on-demand release of multiple drugs following the single administration of a therapeutic agent. Several researchers have explored MDSRS, providing fresh strategies for synergistic cancer therapy. This review article first introduces the main characteristics of MDSRS. It then elaborates on the design principles of MDSRS. Subsequently, it summarizes the various structures of carriers used for constructing MDSRS, including core-shell structure, Layer-by-layer structure, Janus structure and hydrogel. Next, through specific examples, the article emphasizes the application of MDSRS in cancer treatment, focusing on their role in remodeling the tumor microenvironment (TME) and enhancing therapeutic effects through multiple mechanisms. Finally, the article discusses the current limitations and challenges of these systems and proposes potential future solutions. Overall, this review underscores the importance of the sequence and timing of drug therapy in cancer treatment, providing valuable theoretical and technical guidance for pharmaceutical research.

Development and characterization of hydrogel beads with carboxymethyl chitosan/graphene quantum dots@Pectin/MIL-88 for targeted doxorubicin delivery: An adaptable nanocomposite approach

Hydrogels are adaptable substances with a 3D framework able to hold large quantities of water, which is why they are ideal for use in the field of biomedicine. This research project focused on creating a new hydrogel combining carboxymethyl chitosan (CMCS), graphene quantum dots (GQDs), pectin (Pe), and MIL-88 for precise and controlled release of the cancer drug doxorubicin (DOX). The creation of CMCS/GQDs@Pe/MIL-88 hydrogel beads was achieved through an eco-friendly one-step synthesis method. The hydrogel beads were then analyzed using various techniques including FE-SEM, EDX, FT-IR, XRD, BET surface area, DLS, and zeta potential measurements. The hydrogel beads showed great swelling ability and controlled breakdown in different pH environments, mimicking the conditions of the gastrointestinal tract and body. Research on drug loading and release showed that the hydrogel components can be adjusted to control the release of DOX. Cytotoxicity tests in a lab setting using K562 cells demonstrated successful delivery of DOX and the ability to target cancer cells specifically while reducing negative effects. Adding GQDs improved both the imaging abilities and the stability and mechanical characteristics of the hydrogel. This research indicates that the CMCS/GQDs@Pe/MIL-88 combination hydrogel beads show great potential for advanced drug delivery systems, especially in cancer treatment.

Encapsulation of Zataria multiflora essential oil in polyvinyl alcohol/chitosan/gelatin thermo-responsive hydrogel: Synthesis, physico-chemical properties, and biological investigations

Zataria multiflora essential oil is a natural volatile plant product whose therapeutic applications require a delivery platform. Biomaterial-based hydrogels have been extensively used in biomedical applications, and they are promising platforms to encapsulate essential oils. Among different hydrogels, intelligent hydrogels have recently attracted many interests because of their response to environmental stimuli such as temperature. Herein, Zataria multiflora essential oil is encapsulated in a polyvinyl alcohol/chitosan/gelatin hydrogel as a positive thermo-responsive and antifungal platform. According to the optical microscopic image, the encapsulated spherical essential oil droplets reveal a mean size of 1.10 ± 0.64 μm, which are in consistent with the SEM imaging results. Encapsulation efficacy and loading capacity are 98.66 % and 12.98 %, respectively. These results confirm the successful efficient encapsulation of the Zataria multiflora essential oil within the hydrogel. The chemical compositions of the Zataria multiflora essential oil and the fabricated hydrogel are analyzed by gas chromatography-mass spectroscopy (GC-MS) and Fourier transform infrared (FTIR) techniques. It is found that thymol (44.30 %) and γ-terpinene (22.62 %) are the main constituents of the Zataria multiflora essential oil. The produced hydrogel inhibits the metabolic activity of Candida albicans biofilms (~60-80 %), which can be related to the antifungal activity of the essential oil constituents and chitosan. Based on the rheological results, the produced thermo-responsive hydrogel shows a gel-sol viscoelastic transition at a temperature of 24.5 °C. This transition leads to a facile release of the loaded essential oil. The release test depicts that about 30 % of Zataria multiflora essential oil is released during the first 16 min. In addition, 2, 5-diphenyl-2H-tetrazolium bromide (MTT) assay demonstrates that the designed thermo-sensitive formulation is biocompatible with high cell viability (over 96 %). The fabricated hydrogel can be deemed as a potential intelligent drug delivery platform for controlling cutaneous candidiasis due to antifungal effectiveness and less toxicity, which can be a promising alternative to traditional drug delivery systems.