Introduction
Uncontrolled hemorrhage is a major cause of death in civilian and military settings (30 and 80%, respectively), often complicated by infection. This underscores the critical need for rapid, effective hemostatic materials. Natural polysaccharides are promising for this purpose. This study aimed to synthesize a novel powdered hemostatic material using a scalable spray-drying technique for rapid hemorrhage control, leveraging the polyelectrolyte properties of chitosan (CHI) and carboxymethylcellulose (CMC).
Methods
Polyelectrolyte complexes (PECs) were formed by dropwise mixing of CHI (1.5% w/v) and CMC solutions (0.5, 1, and 1.5% w/v). These PECs were then spray-dried (inlet temperature 160°C, outlet temperature 80°C, aspirator 70°C) to yield powdered microgels (1.5Q/1.5CMC; 1.5Q/1.0CMC; and 1.5Q/0.5CMC). The resulting microgels were evaluated for their morphological, physical, thermal, swelling, and hemostatic properties.
Results
ATR-FTIR spectra confirmed electrostatic interactions between amino and carboxyl groups of CHI and CMC in all microgels. The SEM technique revealed an irregular spherical morphology with an average size of 2–3 µm for all microgels. The gel fraction test (GF) showed that 1.5Q/1.5CMC samples had higher crosslinking between CHI and CMC (64.2±1.7%) compared to 1.5Q/1.0CMC (49.9±2.5%) and 1.5Q/0.5CMC (42.9±3.8%). Additionally, 1.5Q/1.5CMC microgels exhibited higher swelling percentages (up to 900%) in PBS solution (pH 7.4) than 1.5Q/1.0CMC and 1.5Q/0.5CMC (up to 600%). TGA analysis indicated similar thermal behavior across all microgels, with three or four degradation stages and a degradation temperature (Tp) around 240°C. Hemolysis testing (ASTM-F756-00) showed all microgels had a hemolysis percentage below 5%, confirming their hemocompatibility. Furthermore, all microgels reduced the coagulation time by 20% in comparison with whole blood without microgels.
Conclusions
Three powdered microgels were successfully obtained using CHI and CMC via spray drying. Among them, 1.5Q/1.5CMC microgels demonstrated superior physicochemical properties, including higher gel fraction and swelling percentages, making them particularly promising for use as hemostatic materials.
