Efficient synthesis, characterization, and application of biobased scab-bionic hemostatic polymers

Under optimized reaction conditions, by directly using the hemostatic drugs 4-aminomethylbenzoic acid (ABA) and tranexamic acid (TA) as separate comonomers of lactic acid (LA), a series of copolymers, P(LA-co-ABA) and P(LA-co-TA), respectively, with different molar feed ratios were designed and synthesized via melt polycondensation and used as biobased polymeric sustained-release hemostatic materials. Their structure, properties and morphology were systematically investigated by Fourier transform infrared spectrometer (FTIR), proton nuclear magnetic resonance (1H NMR), gel permeation chromatography (GPC), X-ray diffraction (XRD), differential scanning calorimetery (DSC), thermogravimetric (TG), scanning electron microscopy (SEM), water contact angle and degradation tests. The degradation rate within 7 weeks can reach 77%. When the molar feed ratios of ABA and TA are 20% and 10%, respectively, the corresponding copolymers have relatively lower crystallinity and smaller water contact angle and exhibit the best coagulation performance. In addition, these powdery copolymers have good application convenience, can form a degradable protective membrane similar to a blood scab on the wound surface and continuously exert hemostatic effects to promote wound healing, as anticipated. A series of polymeric hemostatic materials are prepared in one-step, by using biobased lactic acid monomers and mature hemostatic drugs (4-aminomethylbenzoic acid or tranexamic acid) through direct melt polycondensation. These materials are powdery with rough and irregular surfaces, and the powder particle size is ~8–30 μm, which is beneficial to the application, immediate hemostasis and scab-bionic membrane forming. Moreover, after the degradation of these materials at 37 °C, more monomers will be released, resulting in a higher efficiency and long-term hemostatic function.