Institute of Fundamental Technological Research

Thermoresponsive hydrogels provide a platform for sustained delivery of nanoparticles via nose-to-brain route by resisting mucociliary clearance to the enhanced mean residence time (MRT) of the formulation in the nasal cavity overcoming neurotoxicity induced by uncontrolled delivery of nanoparticles and accumulation in the brain when delivered alone. The reported study presents the synthesis of pullulan (PLN) based nanoparticles (PNP-EHBr) loaded with eletriptan hydrobromide (EHBr) via ionic gelation method having size between 26.65 nm and 29.59 nm after stability studies of 4 h incubation with an average zeta potential of 22.5 ± 0.1 mV and entrapment efficiency of 92.048%. F-127/F-68 based hyaluronic acid-co-pectin hydrogels of EHBr-loaded PLN nanoparticles thermoresponsive hydrogels (HAP-PNP-EHBr/T-Hg) were characterized via Fourier transform infrared spectroscopy (FTIR), X-ray diffraction, thermal analysis (TGA/DSC), and scanning electron microscopy and evaluated for their gelation time, gelation temperature, gel strength, cloud point, sol–gel fraction, ex-vivo permeation, etc. HAP-PNP-EHBr/T-Hg showed drug release in a controlled pattern in both phosphate-buffered saline (PBS) and simulated nasal fluid (SNF) i.e., 90.12 and 87.99, respectively, over 48 h, while PNP-EHBR, 99.44 and 97.53 in PBS and SNF, respectively, over 8 h. The controlled release and absorption of EHBr from HAP-PNP-EHBr/T-Hg and PNP-EHBr was estimated by an in-vivo pharmacokinetic study using high-performance liquid chromatography, MRT and area under the curve (AUC) were increased up to 11.337 ± 0.32 h and 3,104.73 ± 75.841 ng/mL*h, 11.088 ± 0.177 h and 3,906.64 ± 152.86 ng/mL*h in brain and blood respectively after IN administration. This work demonstrates the successful synthesis of a twofold drug delivery system with PLN-based nanoparticles (PNP-EHBr) loaded with EHBr laden F-127/F-68 based hyaluronic acid-co-pectin hydrogels (HAP-PNP-EHBr/T-Hg).

Biodegradable polymers, controlled delivery, nose-to-brain delivery, polymeric nanoparticles, self-assembling micelles, thermoresponsive hydrogels

Bone tissue possesses intrinsic regenerative capabilities to address deformities; however, its ability to repair defects caused by severe fractures, tumor resections, osteoporosis, joint arthroplasties, and surgical reconsiderations can be hindered. To address this limitation, bone tissue engineering has emerged as a promising approach for bone repair and regeneration, particularly for large-scale bone defects. In this study, an injectable hydrogel based on kappa-carrageenan-co-N-isopropyl acrylamide (κC-co-NIPAAM) was synthesized using free radical polymerization and the antisolvent evaporation technique. The κC-co-NIPAAM hydrogel's cross-linked structure was confirmed using Fourier transform infrared spectra (FTIR) and nuclear magnetic resonance (1H NMR). The hydrogel's thermal stability and morphological behavior were assessed using thermogravimetric analysis (TGA) and scanning electron microscopy (SEM), respectively. Swelling and in vitro drug release studies were conducted at varying pH and temperatures, with minimal swelling and release observed at low pH (1.2) and 25 °C, while maximum swelling and release occurred at pH 7.4 and 37oC. Cytocompatibility analysis revealed that the κC-co-NIPAAM hydrogels were biocompatible, and hematoxylin and eosin (H&E) staining demonstrated their potential for tissue regeneration and enhanced bone repair compared to other experimental groups. Notably, digital x-ray examination using an in vivo bone defect model showed that the κC-co-NIPAAM hydrogel significantly improved bone regeneration, making it a promising candidate for bone defects.

Bone regeneration, Injectable hydrogel, Nano-risedronate, Controlled delivery, Nanotechnology

Oral drug delivery systems have innumerable advantages, despite their precedence, the delivery of lipophilic drugs belonging to biopharmaceutical class II and IV, which has challenges associated with their solubility and permeability, leading to the limitations of this route. To address these barriers, nanocarrier systems combined with biomaterials are considered one of the pre-eminent approaches. Therefore, in this study pH-responsive pullulan-based hydrogels were developed, which were loaded with curcumin nanocrystals, micelles and coarse curcumin. In-vitro characterization studies, including dynamic light scattering, Fourier-transform infrared spectroscopy, proton nuclear magnetic resonance, scanning electron microscopy, thermogravimetric analysis, differential scanning calorimetry, and X-ray diffraction supported the development of hydrogels. The swelling index showed that developed hydrogels have significant swelling at pH 7.4, as the optimized formulation shows a “q value” of 5.938% at higher pH and 2.382% at lower pH. Additionally, the nanocrystal-laden hydrogel showed 86.250% drug release at pH 7.4, and better release than micelles and coarse curcumin-laden hydrogel. Moreover, nanocrystals showed a 1-fold increase in the solubility of curcumin, enhanced physical stability, and 82.81% permeation as compared with formulations. Conclusively, the outcome of the studies distinctly revealed a promising approach for successfully developing Pu-g-MAA hydrogels and the inclusion of lipophilic drugs in them.

Nanocrystals, Micelles, Curcumin, Controlled release, pH sensitive, Hydrogels