Cationic gelatin nanoparticles ((+)nGNPs) were prepared by in situ polymerization upon the surfaces of monodispersed gelatin nanoparticles (GNPs) using N-(3-Aminopropyl)methacrylamide (APm) as monomer, which were then decorated with doxorubicin terminated poly(2-methylacryloyloxyethyl phosphorylcholine) (DOX-pMPC) via EDC/NHS conjugation to obtain core–shell nanoparticles ((+)nGNPs@DOX-pMPC) for cancer therapy. The non-fouling pMPC shell could effectively shield the positively charged surface of inner nanoparticle and prevent non-specific protein adsorption, thus endowing the materials with potential for long-acting cancer treatment. Furthermore, the acyl hydrazone bond connecting DOX and pMPC chain could be easily hydrolyzed in the weakly acidic tumor microenvironment. After decladding of the pMPC shell, electropositive (+)nGNPs carrying the drugs can be effectively internalized by cancer cells to induce apoptosis, avoiding undesirable hindrance caused by the superhydrophilic outer layer. On combining the above properties, this drug delivery system can be a promising candidate for long-acting, low-toxicity and high-efficiency cancer therapy.
Massive bleeding from deep penetrating wounds and bacterial infections are serious challenges for clinical and outdoor wound management. In this study, different molar ratios of chitosan (CS) and dopamine (DA) were covalently combined with sodium alginate (SA) through EDC/NHS to form complexes. Then, the cross-linking reaction was performed to form a sponge by adding sodium periodate. The CS 3 /SA/DA 1 compress sponge has rapid blood-triggered recovery properties that can quickly expand to block wounds and prevent bleeding. The CS 3 /SA/DA 1 has better coagulation ability than commercial gelatin sponges and gauze in a mouse liver injury/leg vein model and lethal incompressible hemorrhage model of a rabbit liver defect. The outstanding advantages of CS 3 /SA/DA 1 in degradation performance , antibacterial properties , antioxidation, hemocompatibility , cytocompatibility and histocompatibility present great application prospects in incompressible wound hemostasis.