添加基質細胞衍生因子-1 之明膠/透明質酸水膠混合氫氧基磷灰石用於骨再生之研究

Abstract

根據估計，每年大約執行八十萬件的骨缺損重建手術。因此，骨缺損在骨折治療上一向為臨床醫師的一大挑戰。臨床上對於骨折合併骨缺損的病人，多於進行開放性復位內固定手術時，於骨缺損處填補骨填充物，以利後續的骨癒合。傳統上常用的骨填充物為無機鹽類陶瓷，主要提供骨傳導之作用，但臨床使用上仍有若干缺點，包括身體吸收不易且不具骨誘導作用。透明質酸 (hyaluronic acid, HA)水膠具良好之生物相容性，且易被生物體所吸收，臨床上已有應用於皮下組織之填充。明膠 (gelatin, Gel) 具有良好之生物相容性，是細胞貼附的重要基質，價格低廉，亦被美國食品藥物管理局列為安全的生醫材料。氫氧基磷灰石 (hydroxyapatite, HAP) 擁有與骨相似之鈣磷比，是穩定的鈣磷酸鹽類，亦具有良好之生物相容性及骨傳導性。而先前研究發現基質細胞衍生因子－1 (stromal cell-derived factor-1, SDF-1) 具有骨誘導能力，可促進骨骼之發育及生成。本實驗製備添加SDF-1之明膠／透明質酸複合材料並混合氫氧基磷灰石之複合材料，經由X光繞射分析儀證明材料含有氫氧基磷灰石且與骨組成類似；經由傅立葉紅外線光譜儀證明成功交聯明膠與透明質酸；依據ISO 10993規範，由 WST-1測試，證明本研究複合材料具有良好生物相容性；經由骨誘導測試，證明本研究複合材料具有吸引間質幹細胞之作用；於動物實驗方面，證明本研究復合材料具有促進骨再生之能力。預期本研究製備之複合材料同時具有骨誘導性及骨傳導性，搭配高生物相容特性及可塑性，於骨癒合有促進之效果，希望能應用於骨缺損之臨床治療。

Bone defect remains a challenge in clinical practice, especially in fracture fixation for orthopedic surgery. Large bone defect may not only cause difficulties in fracture reduction and fixation, but also compromise bone healing and eventually lead to delayed union or non-union of bone. Such kind of complications will largely endanger activity level and physical function of these patients. There are huge social and economic cost due to serial hospital stay, sequential operations and clinic follow-ups in order to treat delayed or non-union of bone. When treating a fracture combined with bone defect, most surgeons will try to fill certain kinds of bone substitute to facilitate bone healing. Traditionally, widely used bone substitutes include calcium sulfate, calcium phosphate and hydroxyapatite. These kinds of ceramics mainly act as macro-porous scaffolds to facilitate the in-growth of osteocyte, which so-called osteoconductive effect in bone healing. However, some limitations need to be dealt with, such as slow resorption rate and non-osteoinductive nature. Autografts and allografts are also treatments of choice in large bone defect. But donor site complications in autografts including pain, fracture or wound infection and undiscovered contagious disease in allografts remain unsolved problems. Hyaluronic acid (HA), one of the main components of extracellular matrix, is highly biocompatible, biodegradable and commonly used as clinical application including subdermal filling. Gelatin (Gel) is biocompatible and inexpensive, and it is a good matrix for cell adherent. Hydroxyapatite (HAp) is one of the components of bone, and it is also biocompatible and osteoconductive. Stromal cell-derived factor-1 (SDF-1) has been found capable of recruiting mesenchymal stem cells (MSCs) toward defect site, which can be considered to have a certain degree of osteoinductive effect, resulting in enhancing bone growth and new bone formation. Gelatin/Hyaluronic acid composite mixed with hydroxyapatite (Gel-HA/HAp) in corporation with SDF-1 may possess both osteoinductive and osteoconductive properties. Act in concert with its nature of high biocompatibility, this osteoinductive composite can be applied to clinical treatment for bone defect. The main purpose of this study is to prepare osteoinductive gelatin /hyaluronic acid-based composite and try to prove its potential in enhancement of bone healing via serial material tests, cellular examinations and animal experiments.