電氣紡絲成形之生醫薄膜研發應用

Abstract

電氣紡絲是一種簡單且方便的方法用來製備纖維，以靜電力使聚合物噴向收集板產生連續纖維，纖維直徑可從幾奈米到微米。電氣紡絲是一種有趣的技術用來製備聚乳酸/複合材料。在聚合物噴向收集板過程提中，可藉此設計纖維的表面形貌和孔隙度，以提供最適當的纖維薄膜應用於生物醫學。 在過去的幾十年裡，高分子複合材料取代了許多傳統金屬材料的各種應用。這可能是因為高分子複合材料比起傳統材料具有許多優勢。最重要的優勢之一是高分子複合材料易於加工，可大量生產，降低成本。在大多數的這些應用中，高分子可藉由添加填料來改變其性能，以達到提升材料強度與特殊性能需求。比起其他常規材料高分子複合材料在改變材料性能上更具有優勢。目前這些高分子複合材料已應用在不同領域，從家電製品到航太科技比比皆是。在生醫應用方面本研究以電氣紡絲製備聚左乳酸/ chlorhexidine (CHX)-gluconate可生物降解藥物釋放薄膜，能持續穩定地抑制細菌生長。藉由細菌生長曲線來即時評估藥物釋放薄膜釋放出藥物的速率與細菌生長的關係。另外本研究提出了一種新的想法，以添加碳酸鈣及其同質異構物於聚左乳酸中，並以電氣紡絲製備生物可降解引導組織再生膜或引導骨頭再生膜。碳酸鈣具備良好的生物相容性，而其同質異構物因有不同的晶格結構，意味著具備不同的力學性能。實驗結果顯示碳酸鈣及其具有不同晶格結構的同質異構物，能製備不同機械強度的生物可降解引導組織再生膜或引導骨頭再生膜。此再生膜的機械性質實驗結果顯示，聚左乳酸添加5%霰石較純的聚左乳酸薄膜的降伏強度高出35%。此結果提供一新的觀念，未來將可視需求而選擇合適的碳酸鈣或其同質異構物，藉由添加不同晶體結構的碳酸鈣比例來製備所需強度的生物可降解引導組織再生膜或引導骨頭再生膜以達到更廣泛的生物醫學應用。 本實驗另以電氣紡絲製備抗紫外線高分子微米纖維。而此抗紫外線纖維薄膜以聚左乳酸和常用紫外線吸收劑二苯甲酮- 12與抗氧化劑Chemfos - 168來製備抗紫外線高分子微米纖維。結果顯示，添加紫外線吸收劑二苯甲酮- 12與抗氧化劑Chemfos - 168雖然能皆具備良好的抗紫外線能力，但在降解速率上添加紫外線吸收劑二苯甲酮- 12抗紫外線高分子纖維薄膜卻遠不及抗氧化劑Chemfos - 168抗紫外線高分子納米纖維薄膜。

Electrospinning is a simple and versatile method for fibers preparation, which employs electrostatic forces that strength a polymer jet to generate continuous fibers with diameters ranging from micrometers down to several nanometers. Electrospinning is an interesting technique for spinning PLLA / composites. The process offers an excellent opportunity for designing the surface morphology and porosity of the fibers to provide the most appropriate interface for biomedical application. Over the past few decades, polymer composites have replaced many of the conventional metals/materials in various applications. This trends may arise from the advantages polymer composites offer over conventional materials. The most important advantages of using polymer composites are the ease of processing, productivity, and cost reduction. In many of these applications, the properties of polymers composites are modified using fillers and fibers to suit the high strength/specific properties requirements. Polymer composites offer advantages over other conventional materials when specific properties are required. These composites are finding applications in diverse fields from electronic appliances to spacecrafts. These research presents some possible applications in the field of biomedical thin films. The study found that biodegradable drug delivery membranes that were fabricated from Poly(α-L-alanine) (PLLA) and chlorhexidine (CHX)-gluconate via electrospinning could steadily and continuously inhibit the growth of bacteria. Bacterial growth curves were used to evaluate on a real-time basis the relationship between drug delivery speeds of the membranes and growth rates of bacteria in different phases. Besides, this paper proposes a novel idea, i.e. to produce bio-degradable GTR or GBR membranes with calcium carbonate and its polymorphism, aragonite, through electrospinning. Calcium carbonate enjoys fair bio-compatibility, while its polymorphism has a different lattice structure which means different mechanical properties. We can tell that PLLA with 5% aragonite offered a yield strength than pure PLLA by approximately 35％. There is a potential that adding calcite or aragonite of different percentage can produce membranes with different mechanical strength for wider applications. This article provides a comprehensive review of the ultraviolet resistance ability, bio-degradation and structural differences of UV absorption and anti-oxidation agents. We use the elements (UV absorption and anti-oxidation agents) composite with PLLA by electrospinning in our study. We observed the PLLA/ UV absorption (Benzophenone-12) fiber membranes higher than PLLA membrane 14.9% in UVA ratio. In this experiment, although both are bio-degradable membranes, the the PLLA/ UV absorption (Benzophenone-12) fiber membranes higher than PLLA membrane 61.6% in I875/I1452 Raman intensity ratio. So PLLA Add UV absorption (Benzophenone-12) fiber membranes can achieve good UV resistance and fast bio-degradation.