Mussel-inspired methacrylated gelatin-dopamine/quaternized chitosan/glycerin sponges with self-adhesion, antibacterial activity, and hemostatic ability for wound dressings

It is one of the most emergent challenges to prepare wound dressings for quickly and effectively controlling profuse bleeding in clinical surgery and emergent accident. In this work, a novel strategy has been developed to prepare methacrylated gelatin-dopamine (GelMA-DA)/quaternized chitosan (QCS)/glycerol (Gly) composite sponges with good biocompatibility, tissue self-adhesion, antibacterial activity, and hemostatic ability. Results show that the GelMA-DA/QCS/Gly sponges display good biocompatibility and water absorption capacity. The lap shear strength of the GelMA-DA/QCS/Gly sponge with the GelMA-DA content of 5 W/V% is approximately 128.36 ± 8.45, 125.17 ± 7.18, 138.29 ± 7.94, and 113.83 ± 9.28 kPa for skin, liver, muscle, and fat, respectively. The GelMA-DA/QCS/Gly sponge displays better antibacterial activity against Gram positive and negative bacteria than the commercial Gelatin hemostatic sponge and CS hemostatic sponge. Animal experiments using rat tail and liver bleeding model show that the hemostasis time and blood loss in the GelMA-DA/QCS/Gly sponge group is approximately 33.3 ± 6.7 s and 0.19 ± 0.05 g, respectively, which is also better than that of the commercial Gelatin hemostatic sponge and CS hemostatic sponge. These results demonstrate promising potential of the GelMA-DA/QCS/Gly sponges for applications as hemostatic wound dressings in clinical surgery and emergent treatment.

Laminated chitosan-based composite sponges for transmucosal delivery of novel protamine-decorated tripterine phytosomes: Ex-vivo mucopenetration and in-vivo pharmacokinetic assessments

In the current study, laminated chitosan (CS):hydroxypropyl methylcellulose (HPMC) composite sponges were exploited as solid matrices for buccal delivery of tripterine phytosomes functionalized with novel mucopenetrating protamine layer (PRT-TRI-PHY). Tripterine (TRI) is a herbal drug widely investigated as a potential anticancer candidate against various types of cancers. However, clinical use of TRI is handicapped by its low oral bioavailability. To surmount TRI pharmaceutical obstacles, TRI phytosomes (TRI-PHY) were prepared using solvent evaporation technique then coated with a protamine layer via electrostatic assembly process. The developed PRT-TRI-PHY showed a nano-metric size of 250 nm and positive zeta potential (+21.6 mV). Sponges loaded with PRT-TRI-PHY demonstrated a sustained release profile with superior mucoadhesion characteristics compared with the counterparts loaded with uncoated TRI-PHY. The ex-vivo permeation study via chicken pouch mucosa revealed that sponges loaded with PRT-TRI-PHY demonstrated 2.3-folds higher flux value compared with sponges loaded with uncoated TRI-PHY. Additionally, in-vivo pharmacokinetic study in healthy rabbits revealed the significantly higher bioavailability of PRT-TRI-PHY compared with TRI-PHY with relative bioavailability of 244%. Conclusively, mucoadhesive CS-HPMC sponges loaded with a novel mucopenetrating nanocarrier, PRT-TRI-PHY, could significantly improve the absorption of tripterine via buccal mucosa which would be of prime importance for its clinical utility.