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The rapid increase in the number of stimuli-responsive polymers, also known as smart polymers, has significantly advanced their applications in various fields. These polymers can respond to multiple stimuli, such as temperature, pH, solvent, ionic strength, light, and electrical and magnetic fields, making them highly valuable in both the academic and industrial sectors. Recent studies have focused on developing hydrogels with self-healing properties that can autonomously recover their structural integrity and mechanical properties after damage. These hydrogels, formed through dynamic covalent reactions, exhibit superior biocompatibility, mechanical strength, and responsiveness to stimuli, particularly pH changes. However, conventional hydrogels are limited by their weak and brittle nature. To address this, ionizable moieties within polyelectrolytes can be tuned to create ionically cross-linked hydrogels, leveraging natural polymers such as alginate, chitosan, hyaluronic acid, and cellulose. The integration of ionic liquids into these hydrogels enhances their mechanical properties and conductivity, positioning them as significant self-healing agents. This review focuses on the emerging field of stimuli-responsive ionic-based hydrogels and explores their potential in dermal applications and tissue engineering.

Aim: To develop a glycerol modified liposomes to effectively deliver active agents into posterior segment of the eye for the management of posterior uveitis., Materials and Methods: The modified liposome enhanced with glycerol as an edge activator was fabricated using a 3 2 experimental design with independent variables being soya lecithin (mg) (X 1 ) and glycerol (%) (X 2 ) and vesicle size (nm) (Y 1 ), deformability index (%) (Y 2 ), and entrapment efficiency (%) (Y 3 ) as dependent variable with improve permeability and entrapment efficacy. These modified liposomes were then integrated into pHEMA-based contact lenses via free radical polymerization using different monomer mixture, co-polymer, crosslinker, and photo-initiator to extend drug release., Results and Conclusions: Nano-vesicles resulted in size and deformability index of 200.5 ± 15 nm and 11.58, respectively, with entrapment efficiency of 80.98% of the drug. Moreover, the optimized lenses demonstrated 71%) of swelling and transmittance of 87%). In addition, in vitro release of active component from the therapeutic contact lens demonstrated sustained drug release over 24 h. Whereas ex vivo studies displayed a 5-fold increase in drug permeation, compared to tested conventional eye drops. The results suggested that glycerosomes-loaded contact lens can be a promising alternative for regulated delivery of dexamethasone sodium phosphate in the management of posterior uveitis.

The dermal delivery of peptide therapeutics that are of high molecular weight is a challenge. Cyclosporine A (CsA) is a cyclic undecapeptide with poor aqueous solubility and high molecular weight (1202 Da) indicated for psoriasis. The objective of the study was to evaluate the effect of ionic liquids mixed with the Pluronic F127 matrix in skin permeation of CsA and its efficacy in psoriasis treatment. Choline and geranic acid (CAGE) ionic liquids in a 1:2 molar ratio were mixed with Pluronic F127 (22.7%) and PEG 400 (45%) to prepare an organogel formulation. The CsA-loaded CAGE (CsA-CAGE) and CAGE-Pluronic F127 gels (CsA-CAGE-P gel) were characterized for physical and rheological characteristics. The skin transport studies showed that free CsA did not permeate across the excised porcine skin after 48 h. The amount of CsA permeated across the oleic acid (0.25% v/v) and palmitic acid (0.25% w/v) cotreated skin was found to be 244 ± 4 and 1236 ± 17 μg/cm 2 , respectively. The application of CsA-CAGE and CsA-CAGE-P gel enhanced CsA flux by 110- and 135-fold, respectively, compared with the control. The thermal analysis and biophysical studies changed the barrier property of the skin significantly ( p < 0.05) after incubation with CAGE and CAGE-P gel. The pharmacokinetic studies in the rat model showed that topical application of CsA-CAGE-P gel provided 2.6- and 1.9-fold greater C max and AUC 0 - t , respectively, compared to the control group. In vitro - in vivo level A correlations were established with R 2 values of 0.991 and 0.992 for both linear and polynomial equations for the CsA-CAGE-P gel formulation using the Wagner - Nelson method. The topical application of CsA-CAGE-P gel (10 mg/kg) on an imiquimod-induced plaque psoriatic model reduced the area of the psoriasis and severity index (PASI) score significantly for erythema and scaling, reversing the changes to skin thickness, blood flow rate, and transepidermal water loss. Together, CAGE-Pluronic F127 organogel was developed as an effective topical formulation for the local and systemic delivery of CsA for the treatment of psoriasis., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)