Applications of Hydrogels in Drug Delivery for Oral and Maxillofacial Diseases

Advances in Hydrogels for Periodontitis Treatment

Periodontitis is a common condition characterized by a bacterial infection and the disruption of the body's immune-inflammatory response, which causes damage to the teeth and supporting tissues and eventually results in tooth loss. Current therapy involves the systemic and local administration of antibiotics. However, the existing treatments cannot exert effective, sustained release and maintain an effective therapeutic concentration of the drug at the lesion site. Hydrogels are used to treat periodontitis due to their low cytotoxicity, exceptional water retention capability, and controlled drug release profile. Hydrogels can imitate the extracellular matrix of periodontal cells while offering suitable sites to load antibiotics. This article reviews the utilization of hydrogels for periodontitis therapy based on the pathogenesis and clinical manifestations of the disease. Additionally, the latest therapeutic strategies for smart hydrogels and the main techniques for hydrogel preparation have been discussed. The information will aid in designing and preparing future hydrogels for periodontitis treatment.

Advancements in hydrogel-based drug delivery systems for the treatment of inflammatory bowel disease: a review

Inflammatory bowel disease (IBD) is a chronic disorder that affects millions of individuals worldwide. However, current drug therapies for IBD are plagued by significant side effects, low efficacy, and poor patient compliance. Consequently, there is an urgent need for novel therapeutic approaches to alleviate IBD. Hydrogels, three-dimensional networks of hydrophilic polymers with the ability to swell and retain water, have emerged as promising materials for drug delivery in the treatment of IBD due to their biocompatibility, tunability, and responsiveness to various stimuli. In this review, we summarize recent advancements in hydrogel-based drug delivery systems for the treatment of IBD. We first identify three pathophysiological alterations that need to be addressed in the current treatment of IBD: damage to the intestinal mucosal barrier, dysbiosis of intestinal flora, and activation of inflammatory signaling pathways leading to disequilibrium within the intestines. Subsequently, we discuss in depth the processes required to prepare hydrogel drug delivery systems, from the selection of hydrogel materials, types of drugs to be loaded, methods of drug loading and drug release mechanisms to key points in the preparation of hydrogel drug delivery systems. Additionally, we highlight the progress and impact of the hydrogel-based drug delivery system in IBD treatment through regulation of physical barrier immune responses, promotion of mucosal repair, and improvement of gut microbiota. In conclusion, we analyze the challenges of hydrogel-based drug delivery systems in clinical applications for IBD treatment, and propose potential solutions from our perspective.

Synthesis and Characterization of Alginate Gel Beads with Embedded Zeolite Structures as Carriers of Hydrophobic Curcumin

Alginate-based beads containing a porous zeolite filler were developed as carriers of bioactive compounds with a hydrophobic nature, such as curcumin (Cur). Curcumin, a natural pigment extracted from the turmeric (Curcuma longa) plant, exhibits antioxidant, anti-inflammatory, anticarcinogenic, and antiviral properties. To enhance the bioavailability of the drug, curcumin needs to be encapsulated in a suitable carrier that improves its dispersibility and solubility. Commercial A-type zeolites (Z5A) were used as curcumin-binding agents and they were immobilized within the alginate gel beads by cross-linking in calcium chloride solution during an extrusion dripping process. The process parameters (alginate and CaCl2 concentrations, needle gauge, collecting distance) were optimized to fabricate beads with good sphericity factor and 1.5-1.7 mm diameter in their hydrated state. The chemical structure of the gel beads was assessed using FTIR spectroscopy, while their thermal stability was evaluated through differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Due to the alginate matrix, the composite Alg/ZA5-Cur beads possess pH-responsive properties. In addition, the gel beads were modified by chitosan (CS) to enhance the stability and control the degradation behavior of the gel matrix. The swelling behavior and the degradation of the beads were analyzed in physiological solutions with different pH values. Results demonstrate the stabilizing and protective effect of the chitosan coating, as well as the reinforcing effect of the zeolite filler. This makes the pH-responsive alginate gel beads good candidates for the delivery of lipophilic drugs to specific inflammatory sites.

[Latest Findings on Hydrogel Drug Delivery Systems in the Treatment of Periodontitis]

Hydrogel drug delivery systems possess unique structures and properties and hence can be injected and retained in the periodontal pocket for slow and controlled release of medications with antibacterial, anti-inflammatory, and periodontal tissue regeneration-promotional effects. Due to their safety, practicability, and effectiveness, they show great potential in the treatment of periodontitis. In this paper, we gave an overview of hydrogel drug delivery systems in the treatment of periodontitis, summing up the classification and forms of the drugs delivered and the strengths and weaknesses of common types of hydrogel matrixes. In addition, we discussed properties required for hydrogel drug delivery systems applicable in the treatment of periodontitis, including a certain level of viscosity, suitable degradation cycle, and temperature sensitivity. Finally, we summarized the stimulus responsiveness types of hydrogel drug delivery systems applicable in the treatment of periodontitis, including pH-responsiveness, enzyme-responsiveness, reactive oxygen species-responsiveness, light-responsiveness, and sugar-responsiveness. In the future, researchers should make further investigation into the clinical efficacy of hydrogel drug delivery systems and promote their translation into clinical applications. Additionally, hydrogel drug delivery systems carrying biologic drugs could be further investigated to promote advancement in the field of periodontal tissue regeneration. Furthermore, the response sources, realization strategies, and safe preparation methods of smart hydrogel drug delivery systems should also be further clarified and explored to achieve drug delivery of better efficiency and safety. In addition to drug delivery, hydrogel matrixes with medicinal values also show great promises.