Hydrogel-Forming Microneedles with Applications in Oral Diseases Management

Abstract

Controlled drug delivery in the oral cavity poses challenges such as bacterial contamination, saliva dilution, and inactivation by salivary enzymes upon ingestion. Microneedles offer a location-specific, minimally invasive, and retentive approach. Hydrogel-forming microneedles (HFMs) have emerged for dental diagnostics and therapeutics. HFMs penetrate the stratum corneum, undergo swelling upon contact, secure attachment, and enable sustained transdermal or transmucosal drug delivery. Commonly employed polymers such as polyvinyl alcohol (PVA) and polyvinyl pyrrolidone are crosslinked with tartaric acid or its derivatives while incorporating therapeutic agents. Microneedle patches provide suture-free and painless drug delivery to keratinized or non-keratinized mucosa, facilitating site-specific treatment and patient compliance. This review comprehensively discusses HFMs’ applications in dentistry such as local anesthesia, oral ulcer management, periodontal treatment, etc., encompassing animal experiments, clinical trials, and their fundamental impact and limitations, for example, restricted drug carrying capacity and, until now, a low number of dental clinical trial reports. The review explores the advantages and future perspectives of HFMs for oral drug delivery.

Applications and prospects of microneedles in tumor drug delivery

“…The microneedles will be removed after use and not remain in the tissue. 64 Turner et al 65 used swelling microneedles to absorb and release drugs (Fig. 2(d)).…”

“…52–54 Most of the materials for preparing swelling microneedles are hydrogels. 64 The materials for preparing dissolving microneedles are divided into soluble and biodegradable materials. Soluble materials include HA, 104,105 PVP, 106,107 PVA, 107 and phthalate cellulose.…”

Recent Advances in Functional Hydrogels for Treating Dental Hard Tissue and Endodontic Diseases

“…A hydrogel is a kind of porous material with a 3D network structure and shows huge application potential in the biomedical field. − By introducing hydrogen bonding or dynamic ion interactions, the strength and adhesion of hydrogels can be effectively improved. − In addition, due to adjustable water content and drug loading/releasing, functional hydrogels have potential applications in oral disease treatment, − such as mucosa healing, oral ulcers, periodontitis treatment, etc. (Figure ).…”

Fast-Embeddable Grooved Microneedles by Shear Actuation for Accurate Transdermal Drug Delivery

“…With lengths ranging from 50 to 2000 microns and widths ranging from 10 to 300 microns, MNs can penetrate the outermost layer of dead skin, known as the stratum corneum, to effectively reach viable cells and interstitial fluid in the epidermis layer for optimal drug delivery [ 8 , 9 ]. In terms of drug delivery mechanisms, MNs can be categorized into five types: solid, hollow, coated, dissolving, or hydrogel-forming MNs [ 1 , 2 , 3 , 4 , 10 , 11 , 12 ]. Recently, cryogenic MNs have been developed for the transdermal delivery of living cells [ 13 ].…”