【作者】 王强；

【导师】 何素芹； 徐琬琳；

【作者基本信息】 郑州大学 ， 材料科学与工程， 2025， 硕士

【摘要】 皮肤作为人类最大的器官却也是非常脆弱的,正常皮肤伤口愈合包括四个阶段:止血期、炎症期、增殖期、和重构期。糖尿病是一种以高血糖为特征的代谢性疾病,其伤口愈合具有缓慢和难愈合的特点,严重影响了患者的日常生活。糖尿病患者一旦形成伤口,由于自身高水平的血糖,细菌侵入的风险大大增加,进而导致大量的氧化应激,在炎症反应阶段巨噬细胞转型困难,血管生成受损,伤口愈合进程大大减缓。因此,设计和制备针对糖尿病伤口的敷料对患者伤口愈合至关重要。水凝胶作为一种新兴敷料材料在伤口愈合领域应用广泛。与传统敷料相比,水凝胶具有优异的生物相容性,不仅可以为伤口提供物理屏障,湿润伤口环境,还可以通过负载相关药物对伤口进行持续调控,赋予敷料抗菌、抗氧化、炎症调节以及血管生成等多种功能,有望促进慢性伤口的愈合。基于上述挑战和要求,本课题设计了具有促进糖尿病伤口愈合效应的多功能双层纳米复合水凝胶敷料。本论文的研究内容和实验结果主要包括以下几个方面:（1）P/PVA水凝胶的制备及性能研究以枝化聚乙烯亚胺（b-PEI）为原料,通过接枝4-羧基苯硼酸（PBA）制备（PEI-PBA）。利用PEI-PBA与聚乙烯醇（PVA）间硼酸酯键和氢键相互作用制备了一系列自交联PEI-PBA/PVA（P/PVA）水凝胶。实验结果表明,P/PVA水凝胶呈现三维多孔结构,具有良好的溶胀能力,能够对伤口渗出液做出良好的吸收。流变测试结果显示P/PVA水凝胶具有良好的稳定性;P/PVA15水凝胶在30分钟时对DPPH和ABTS两种自由基的清除率分别达到了52.5%和78.8%,具有良好的自由基清除能力。抗菌实验显示P/PVA15水凝胶对金黄色葡萄球菌和大肠杆菌的抗菌率可以达到93.7%和95.1%。P/PVA水凝胶还具有优异的生物相容性,有望用于伤口敷料。（2）GM/GP双层水凝胶的制备及性能研究选择生物基明胶作为水凝胶基体,制备多巴胺接枝甲基丙烯酰化明胶（GelMA-DA）,以水和甘油（水:甘油=7:3）为溶剂制备了GelMA-DA/PEI-PBA（GP）下层水凝胶,赋予其对伤口的治疗作用。通过甲基丙烯酰化明胶（GelMA）与甲基丙烯酸（MAA）引发剂交联得到上层水凝胶（GM）,提供敷料的力学强度。SEM结果表明成功制备了双层GM/GP水凝胶。通过调控GelMA-DA的比例使下层水凝胶具有良好的溶胀性能和降解性能、以及出色的保水能力,下层水凝胶在室温下保存三天仍能保存80%以上的质量。下层GP20水凝胶对DPPH和ABTS自由基清除率分别为67.5%和89.2%。流变测试结果显示下层水凝胶在0.1-100 Hz的扫描频率范围内具有良好的稳定性。通过调控GelMA与MAA的比例使上层水凝胶具有良好的力学性能,在GelMA:MAA=10:10时GM水凝胶的拉伸强度达到0.3 MPa,断裂伸长率为250%,压缩模量达到69 k Pa。（3）GM/GP@MB复合水凝胶的制备及其糖尿病伤口愈合应用抗菌、抗氧化、抗炎等是糖尿病伤口敷料不可或缺的性能。基于前两部分工作的探索,通过水热法制备了具有光热效应的二氧化钼纳米颗粒（M:MoO₂ NP）、以及具有一氧化氮（NO）释放能力的N,N’-二仲丁基-N,N’-二亚硝基-1,4-苯二胺（B:BNN6）,通过静电相互作用将BNN6负载到MoO₂表面（MB:MoO₂@BNN6NP）,并将纳米粒子掺入水凝胶制备了一系列GP@M、GM/GP@M、GM/GP@MB纳米复合水凝胶。GM/GP@MB水凝胶具有优异的光热转化能力,在0.5 W/cm²近红外激光发射器辐照3分钟温度可以达到50℃,GM/GP@MB凝胶10分钟内释放NO浓度可以达到3μM。GM/GP@MB水凝胶具有优异的生物相容性和抗菌性,可以促进细胞迁移,以及巨噬细胞的极化,对细胞内的ROS也具有良好的清除能力,动物实验显示该水凝胶可促进糖尿病小鼠伤口的愈合。GM/GP@MB水凝胶对金黄色葡萄球菌和大肠杆菌的杀菌率接近100%,HUVECs细胞在水凝胶浸提液中细胞存活率大于80%,溶血率低于3%,糖尿病小鼠皮肤创面在14天时完全愈合。本研究通过光热作用及气体疗法实现了对糖尿病伤口微环境的调控,这为此类伤口敷料的制备和临床应用提供了基础。更多还原

【Abstract】 The skin,as the largest organ of the human body,was highly vulnerable.Normal wound healing in skin involved four sequential phases:hemostasis,inflammation,proliferation,and remodeling.Diabetes mellitus,a metabolic disorder characterized by hyperglycemia,was associated with delayed and impaired wound healing,severely affecting patients’quality of life.Once wounds formed in diabetic patients,the elevated blood glucose levels significantly increased the risk of bacterial invasion,leading to excessive oxidative stress.During the inflammatory phase,macrophage polarization was compromised,angiogenesis was impaired,and the wound healing process was substantially delayed.Consequently,designing and fabricating specialized dressings for diabetic wounds was crucial for promoting healing.Hydrogels,as an emerging dressing material,had been widely explored in wound management.Compared to traditional dressings,hydrogels exhibited excellent biocompatibility.They not only provided physical barriers and maintained moist wound environments but also enabled sustained therapeutic delivery through drug-loading capabilities.These functional hydrogels could be engineered with antibacterial,antioxidant,anti-inflammatory,and pro-angiogenic properties,demonstrating significant potential for accelerating chronic wound repair.To address these challenges and requirements,this study developed a multifunctional bilayer nanocomposite hydrogel dressing tailored for diabetic wound healing.The research content and experimental findings of this thesis primarily encompassed the following aspects:（1）Preparation and Property Investigation of PEI-PBA/PVA HydrogelsA series of self-crosslinking PEI-PBA/PVA（P/PVA）hydrogels were prepared using branched polyethyleneimine（b-PEI）grafted with tetracarboxyphenylboronic acid（PBA）（denoted as PEI-PBA）through boronate ester bonds and hydrogen bonding interactions with polyvinyl alcohol（PVA）.Experimental results demonstrated that the P/PVA hydrogels exhibited a three-dimensional porous structure and excellent swelling capacity,enabling efficient absorption of wound exudate.Rheological tests revealed favorable mechanical stability of the hydrogels.The P/PVA15 hydrogel achieved DPPH and ABTS radical scavenging rates of 52.5%and 78.8%at 30 minutes,respectively,indicating robust antioxidant activity.Antibacterial assays showed that the P/PVA15 hydrogel exhibited inhibition rates of 93.7%against Staphylococcus aureus and 95.1%against Escherichia coli.Furthermore,the P/PVA hydrogels demonstrated excellent biocompatibility,highlighting their promising potential for wound dressing applications.（2）Preparation and Characterization of GM/GP Bilayer HydrogelsBio-based gelatin was employed as the hydrogel matrix to synthesize dopamine-grafted methacrylated gelatin（GelMA-DA）,and a lower-layer GelMA-DA/PEI-PBA（GP）hydrogel was fabricated using a water-glycerol solvent system（water:glycerol=7:3）to confer therapeutic functionality for wound healing,while the upper-layer hydrogel（GM）was prepared by crosslinking methacrylated gelatin（GelMA）with methacrylic acid（MAA）as an initiator to provide mechanical strength for the dressing.SEM analysis confirmed the successful construction of the bilayer GM/GP hydrogel.By optimizing the GelMA-DA ratio in the lower layer,the hydrogel demonstrated superior swelling capacity,controlled degradability,and exceptional water retention,retaining over 80%of its initial mass after 3 days at room temperature.The GP20formulation exhibited radical scavenging rates of 67.5%for DPPH and 89.2%for ABTS,alongside consistent viscoelastic behavior across a broad frequency range（0.1–100 Hz）in rheological tests.Meanwhile,mechanical optimization of the upper GM layer through adjustment of the GelMA:MAA ratio to 10:10 achieved a tensile strength of 0.3 MPa,an elongation at break of 250%,and a compressive modulus of 69 k Pa,integrating the therapeutic lower layer with the mechanically reinforced upper layer to demonstrate synergistic potential for advanced wound management applications.（3）Preparation of GM/GP@MB composite hydrogel and its application for diabetic wound healingAntimicrobial,antioxidant,and anti-inflammatory functionalities were indispensable for diabetic wound dressings.Building on previous investigations,molybdenum dioxide nanoparticles（M:MoO₂ NP）with photothermal effects were synthesized via a hydrothermal method,and N,N’-di-sec-butyl-N,N’-dinitroso-1,4-phenylenediamine（B:BNN6）,a nitric oxide（NO）-releasing compound,was electrostatically loaded onto the MoO₂ surface to form MB:MoO₂@BNN6 NP.These nanoparticles were incorporated into the hydrogel layer to fabricate GP@M,GM/GP@M,and GM/GP@MB nanocomposite hydrogels.The GM/GP@MB hydrogel exhibited exceptional photothermal conversion efficiency,reaching 50°C within 3 minutes under 0.5 W/cm² near-infrared laser irradiation.Concurrently,it released NO at a concentration of 3μM within 10 minutes.The GM/GP@MB hydrogel demonstrated excellent biocompatibility and antimicrobial activity,achieving near-complete eradication（>99.9%）of S.aureus and E.coli.It significantly promoted cell migration,facilitated macrophage polarization,and effectively scavenged intracellular reactive oxygen species（ROS）.In vivo experiments confirmed accelerated wound closure in diabetic mice,with full healing achieved within 14 days.Furthermore,the hydrogel showed high biosafety,as evidenced by>80%viability of HUVECs in its extracts and a hemolysis rate below 3%.This study established a synergistic strategy combining photothermal therapy and gas therapy to regulate the diabetic wound microenvironment,providing a foundational framework for the development and clinical translation of multifunctional therapeutic platforms for chronic wound management.更多还原