【作者】 孙凯；

【导师】 孙凯；

【作者基本信息】 大连理工大学 ， 生物工程， 2025， 硕士

【摘要】 慢性创口由于其复杂的病理微环境及难以预测的愈合过程,已成为临床治疗中的重大挑战,因此及时有效的干预创面微环境对于慢性创口的治疗至关重要。纱布等传统敷料因其快速止血、保护伤口的能力常用于临床实践,但这些敷料主要依赖于被动愈合机制,难以应对慢性创面的多因素病理状态。近年来智能化敷料,尤其水凝胶微针,能够主动调节伤口微环境内的关键理化参数,实现组织再生并加速伤口愈合。然而,当前的智能敷料并未系统集成结合治疗和诊断,仅限于单侧作用,并不能满足患者现有的治疗-及时反馈-改进治疗方案的需求。因此,开发集诊断与治疗功能于一体的智能敷料,构建治疗-反馈机制,是实现慢性创口有效治疗与个性化护理的关键因素。本课题设计并构建了一种具有治疗和实时监测功能的治疗水凝胶微针贴片（THMN）,通过搭载超氧化物歧化酶（SOD）/过氧化氢酶（CAT）酶作为治疗剂,定向调控慢性创口的高浓度活性氧（ROS）,促进创面快速愈合;并搭载氧敏感传感器半导体聚合物量子点（Pdot）,原位监测创面组织氧浓度变化,对创面愈合状态实施动态评估,通过阶段性评估结果对治疗剂和护理方案进行及时改进。研究内容如下:（1）设计制备水凝胶微针,设计了以聚丙烯酰胺（PAM）作为针尖材料,采用双层背衬聚乙烯醇（PVA）/PAM双网络水凝胶柔性膜,粘附于医用级聚氨酯（PU）膜的水凝胶微针,对微针的透光性,机械性能,包载与传质性能以及生物相容性进行了表征,验证了所制备的微针完整透明,可穿透皮肤并实现组织粘附,并能包载生物酶、实现小分子传质,且具有良好的生物相容性。（2）THMN的微环境调控,首先通过治疗剂梯度搭载实验比较ROS清除率,筛选合适的治疗剂搭载量（20μg SOD,20μg CAT）,在酶级联作用下微针贴片实现ROS的有效清除（H₂O₂清除率94.64±4.66%,O₂^-·清除率93.20±3.77%）,调控微环境中过高的ROS。在慢性创口的动物模型中,表现出优异的治疗作用,伤口闭合时间较未经处理组缩短了约33%,较纯材料微针组缩短了26%,有效促进了慢性创口的愈合。（3）THMN的微环境诊断,首先验证了Pdot对于生理范围溶解氧良好的线性相关性（R²=0.996）,之后在微针中搭载Pdot构建比率型光学传感器,并表征了水凝胶微针在体外溶液中对溶解氧的连续监测（R²=0.857）,可定性的反映溶解氧浓度改变过程。将THMN贴敷于创口,通过荧光信号监测创面组织氧浓度变化,评估慢性伤口治疗过程中,然而由于受到环境中的氧气影响,THMN评估创面愈合状态效果欠佳,但因其能通过荧光强度反映氧气浓度变化,表明仍具有一定的应用潜力。综上所述,本研究构建了一种兼具抗氧化治疗功能与氧浓度响应能力的水凝胶微针贴片（THMN）,在治疗慢性创口的过程中,以贴片荧光强度作为反馈信号,评估创面愈合状态。尽管在实际创面环境下的监测效果受限,尚未实现稳定的动态反馈,但为后续智能敷料中传感功能的优化集成提供了重要参考,为诊疗一体化智能微针敷料的设计提供了可行性验证,为慢性伤口管理系统的智能化发展提供了有价值的探索方向。更多还原

【Abstract】 Chronic wounds,due to their complex pathological microenvironment and unpredictable healing process,pose a significant challenge in clinical treatment.Timely and effective intervention in the wound microenvironment is therefore critical for promoting wound healing.Traditional dressings such as gauze are widely used in clinical practice,owing to their ability to rapidly stop bleeding and protect the wound;however,these materials primarily rely on passive healing mechanisms,and are inadequate for addressing the multifactorial pathological conditions of chronic wounds.In recent years,smart dressings—particularly hydrogel microneedles—have emerged as promising tools capable of actively modulating key physicochemical parameters within the wound microenvironment,thereby facilitating tissue regeneration and accelerating healing.Nevertheless,most current smart dressings are limited to either therapeutic or diagnostic functions and lack an integrated system capable of both.As a result,they fail to meet the clinical demand for synchronized treatment-real time feedback-and adaptive therapeutic adjustment.Therefore,the development of smart dressings integrating both diagnostic and therapeutic functions,along with the establishment of treatment-feedback mechanisms,is a key factor for achieving effective treatment and personalized care of chronic wounds.In this study,a therapeutic hydrogel microneedle patch(THMN)with integrated treatment and real-time monitoring functions was designed and fabricated.By incorporating superoxide dismutase(SOD)and catalase(CAT)as therapeutic agents,the system enables targeted regulation of excessive reactive oxygen species(ROS)in chronic wounds,thereby accelerating wound healing.Additionally,oxygen-sensitive semiconducting polymer dots(Pdots)were incorporated as sensors to enable in situ monitoring of oxygen concentration changes in the wound tissue,allowing for dynamic evaluation of the wound healing status.The staged assessment results provide a basis for timely adjustments to therapeutic agents and nursing strategies.The specific research contents are as follows:(1)Design and fabrication of hydrogel microneedles.Hydrogel microneedles were designed and fabricated using polyacrylamide(PAM)as the needle tip material,combined with a bilayer backing composed of a polyvinyl alcohol(PVA)/PAM double-network hydrogel film,that adhered to a medical-grade polyurethane(PU)membrane.The microneedles were systematically characterized for optical transparency,mechanical strength,biomolecule loading and diffusion capability,as well as biocompatibility.The results confirmed that the fabricated microneedles were fully transparent,capable of penetrating the skin and adhering to tissue,effectively encapsulating bioenzymes,allowing small-molecule transport,and exhibiting excellent biocompatibility.(2)Microenvironmental regulation of THMN.To evaluate the ROS-scavenging performance,a gradient loading experiment of therapeutic enzymes was conducted,and an optimal loading dose of 20?μg superoxide dismutase(SOD)and 20?μg catalase(CAT)was identified.Under the synergistic cascade action of these enzymes,the microneedle patch effectively eliminated excessive reactive oxygen species(ROS),achieving a hydrogen peroxide(H?O?)clearance rate of 94.64?±?4.66%and a superoxide anion(O??·)clearance rate of93.20?±?3.77%.In a chronic wound animal model,the THMN patch exhibited excellent therapeutic efficacy,shortening the wound closure time by approximately 33%compared to the untreated group,and by 26%compared to the blank microneedle group,thereby effectively promoting the healing of chronic wounds.(3)Microenvironmental diagnosis of THMN.Firstly,the Pdots demonstrated a strong linear correlation with dissolved oxygen within the physiological range(R2=0.996).Subsequently,Pdots were incorporated into the microneedles to construct a ratiometric optical sensor,and the hydrogel microneedles were characterized for continuous dissolved oxygen monitoring in vitro(R2=0.857),qualitatively reflecting changes in dissolved oxygen concentration.THMN patches were applied to wounds to monitor changes in oxygen concentration within wound tissue via fluorescence signals,aiming to evaluate the chronic wound healing process.However,due to interference from environmental oxygen,the THMN showed limited effectiveness in assessing wound healing status.Nevertheless,its ability to reflect oxygen concentration changes through fluorescence intensity indicates promising potential for future applications.In summary,this study developed a hydrogel microneedle patch(THMN)integrating both antioxidant therapeutic functions and oxygen concentration responsiveness.During the treatment of chronic wounds,the fluorescence intensity of the patch was used as a feedback signal to evaluate the wound healing status.Although monitoring performance in the actual wound environment was limited and stable dynamic feedback was not yet achieved,this work provides important insights for the optimized integration of sensing functions in future smart dressings.It also offers a feasibility validation for the design of integrated diagnostic and therapeutic intelligent microneedle dressings and presents a valuable direction for the intelligent development of chronic wound management systems.更多还原