傷口修補的過程可劃分為三個相互影響的過程:凝血發炎期、增生期與重組期，在此期間以角質細胞、纖維母細胞與血管內皮細胞為主的遷徙與增殖，掌握了傷口床周遭血管新生與傷口癒合的速度。然而糖尿病患者由於代謝功能異常，進而破壞或延遲癒合過程，致使末肢的傷口容易發展成慢性傷口，稱為糖尿病潰瘍。近年來硫化氫 (Hydrogen sulfide, H2S) 氣體在生物體內作為信息傳遞物質的作用機制逐漸被解開，文獻指出硫化氫能夠提升細胞增殖、遷徙與血管結構的形成。二烯丙基二硫 (Diallyl disulfide, DADS) 是一種從大蒜素分解後得到的有機硫化合物，其必須與細胞內的麩胱甘肽 (Glutathione, GSH) 或其他含硫還原劑反應後才能生成硫化氫，因此可避免在投遞外源性硫化氫時，常因半衰期短且瞬時濃度太高導致無法有效地供細胞利用的問題。本研究利用氯化鈣與碳酸鈉行複分解反應生成的碳酸鈣 (Calcium carbonate)當作皮克林乳化法 (Pickering emulsion) 的乳化劑，製備出內為DADS，外為碳酸鈣的核殼結構粒子 (DADS@CCMPs)。透過這種核殼結構的保護，可以延緩DADS被水解，進而使硫化氫能緩釋更久；更能透過碳酸鈣外殼阻止DADS的自聚集現象，並於傷口較酸性的環境下能釋放鈣離子以促進傷口癒合。在細胞實驗方面，藉由人類臍帶靜脈內皮細胞 (human umbilical vein endothelial cell, HUVECs) 與人類表皮層角質細胞 (human epidermis keratinocyte) 的增殖、遷徙與管狀形成實驗，發現本硫化氫緩釋系統具有誘導血管新生與傷口癒合的潛力。在動物實驗方面，本研究針對第二型糖尿病db/db小鼠背上的傷口進行治療，發現相對於直接投藥以及未治療之組別，投以DADS@CCMPs可顯著提升傷口癒合速度。此結果證實本系統能夠有效促進慢性傷口之癒合。

Patients with diabetes mellitus are prone to develop refractory wounds. They exhibit reduced synthesis and levels of circulating hydrogen sulfide (H2S), which is an ephemeral gaseous molecule. Physiologically, H2S is an endogenous gasotransmitter with multiple biological functions. Pickering emulsion method is utilized to prepare a microparticle system that comprises calcium carbonate to encapsulate diallyl disulfide (DADS), a highly water-labile H2S donor. An emulsion technique that can minimize the loss of water-labile active compounds during emulsification must be developed. The as-prepared microparticles (DADS@CCMPs) provide an in situ depot for the sustained release of exogenous H2S under physiological conditions. Also, it wound release calcium ions when DADS@CCMPs encountered chronic wound which is acidic environment. The sustained release of H2S and calcium ions wound promote several cell behaviors, including epidermal/endothelial cell proliferation and migration, as well as angiogenesis, accelerating the healing of full-thickness wounds in diabetic mice. These experimental results reveal the strong potential of DADS@CCMPs for the sustained release of H2S for the treatment of diabetic wounds.

1. Gurtner, G.C., et al., Wound repair and regeneration. Nature, 2008. 453(7193): p. 314-321.
2. Boateng, J.S., et al., Wound Healing Dressings and Drug Delivery Systems: A Review. Journal of Pharmaceutical Sciences. 97(8): p. 2892-2923.
3. O’Loughlin, A. and T. O’Brien, Topical Stem and Progenitor Cell Therapy for Diabetic Foot Ulcers, in Stem Cells in Clinic and Research, A. Gholamrezanezhad, Editor. 2011, InTech: Rijeka. p. Ch. 23.
4. Shanik, M.H., et al., Insulin Resistance and Hyperinsulinemia. Is hyperinsulinemia the cart or the horse?, 2008. 31(Supplement 2): p. S262-S268.
5. Organization, W.H. Diabetes. 2017 July.
6. Ceriello, A., Coagulation activation in diabetes mellitus: the role of hyperglycaemia and therapeutic prospects. Diabetologia, 1993. 36(11): p. 1119-1125.
7. Brem, H. and M. Tomic-Canic, Cellular and molecular basis of wound healing in diabetes. Journal of Clinical Investigation, 2007. 117(5): p. 1219-1222.
8. Eming, S.A., T. Krieg, and J.M. Davidson, Inflammation in Wound Repair: Molecular and Cellular Mechanisms. Journal of Investigative Dermatology, 2007. 127(3): p. 514-525.
9. Edwards, R. and K.G. Harding, Bacteria and wound healing. Curr Opin Infect Dis, 2004. 17(2): p. 91-6.
10. Potter, C.F., et al., Effects of hyperoxia on nitric oxide synthase expression, nitric oxide activity, and lung injury in rat pups. Pediatr Res, 1999. 45(1): p. 8-13.
11. Saap, L.J. and V. Falanga, Debridement performance index and its correlation with complete closure of diabetic foot ulcers. Wound Repair Regen, 2002. 10(6): p. 354-9.
12. Wang, R., Physiological implications of hydrogen sulfide: a whiff exploration that blossomed. Physiol Rev, 2012. 92(2): p. 791-896.
13. Savage, J.C. and D.H. Gould, Determination of sulfide in brain tissue and rumen fluid by ion-interaction reversed-phase high-performance liquid chromatography. J Chromatogr, 1990. 526(2): p. 540-5.
14. Goodwin, L.R., et al., Determination of sulfide in brain tissue by gas dialysis/ion chromatography: postmortem studies and two case reports. J Anal Toxicol, 1989. 13(2): p. 105-9.
15. Barr, L.A. and J.W. Calvert, Discoveries of hydrogen sulfide as a novel cardiovascular therapeutic. Circ J, 2014. 78(9): p. 2111-8.
16. Wallace, J.L., Hydrogen sulfide-releasing anti-inflammatory drugs. Trends Pharmacol Sci, 2007. 28(10): p. 501-5.
17. Wen, Y.D., et al., Hydrogen sulfide protects HUVECs against hydrogen peroxide induced mitochondrial dysfunction and oxidative stress. PLoS One, 2013. 8(2): p. e53147.
18. Yang, G., et al., H2S as a physiologic vasorelaxant: hypertension in mice with deletion of cystathionine gamma-lyase. Science, 2008. 322(5901): p. 587-90.
19. Coletta, C., et al., Hydrogen sulfide and nitric oxide are mutually dependent in the regulation of angiogenesis and endothelium-dependent vasorelaxation. Proc Natl Acad Sci U S A, 2012. 109(23): p. 9161-6.
20. Papapetropoulos, A., et al., Hydrogen sulfide is an endogenous stimulator of angiogenesis. Proc Natl Acad Sci U S A, 2009. 106(51): p. 21972-7.
21. Li, L., et al., GYY4137, a novel hydrogen sulfide-releasing molecule, protects against endotoxic shock in the rat. Free Radic Biol Med, 2009. 47(1): p. 103-13.
22. Li, L., et al., Characterization of a novel, water-soluble hydrogen sulfide-releasing molecule (GYY4137): new insights into the biology of hydrogen sulfide. Circulation, 2008. 117(18): p. 2351-60.
23. Li, L. and P.K. Moore, Putative biological roles of hydrogen sulfide in health and disease: a breath of not so fresh air? Trends Pharmacol Sci, 2008. 29(2): p. 84-90.
24. Cai, W.J., et al., The novel proangiogenic effect of hydrogen sulfide is dependent on Akt phosphorylation. Cardiovasc Res, 2007. 76(1): p. 29-40.
25. Dhaese, I., I. Van Colen, and R.A. Lefebvre, Mechanisms of action of hydrogen sulfide in relaxation of mouse distal colonic smooth muscle. Eur J Pharmacol, 2010. 628(1-3): p. 179-86.
26. Benavides, G.A., et al., Hydrogen sulfide mediates the vasoactivity of garlic. Proc Natl Acad Sci U S A, 2007. 104(46): p. 17977-82.
27. Lee, Z.W., et al., The slow-releasing hydrogen sulfide donor, GYY4137, exhibits novel anti-cancer effects in vitro and in vivo. PLoS One, 2011. 6(6): p. e21077.
28. Wallace, J.L., et al., Hydrogen sulfide enhances ulcer healing in rats. Faseb j, 2007. 21(14): p. 4070-6.
29. Caliendo, G., et al., Synthesis and biological effects of hydrogen sulfide (H2S): development of H2S-releasing drugs as pharmaceuticals. J Med Chem, 2010. 53(17): p. 6275-86.
30. Choi, C.S. and Y.W. Kim, A study of the correlation between organic matrices and nanocomposite materials in oyster shell formation. Biomaterials, 2000. 21(3): p. 213-22.
31. Liu, Y., et al., Calcium Carbonate Crystallization in the Presence of Casein. Crystal Growth & Design, 2012. 12(10): p. 4720-4726.
32. Kim, S. and C. Beum Park, Bio-Inspired Synthesis of Minerals for Energy, Environment, and Medicinal Applications. Vol. 23. 2013. 10-25.
33. Boyjoo, Y., V.K. Pareek, and J. Liu, Synthesis of micro and nano-sized calcium carbonate particles and their applications. Journal of Materials Chemistry A, 2014. 2(35): p. 14270-14288.
34. Wei, W., et al., Preparation of Hierarchical Hollow CaCO3 Particles and the Application as Anticancer Drug Carrier. Journal of the American Chemical Society, 2008. 130(47): p. 15808-15810.
35. Min, K.H., et al., pH-Controlled Gas-Generating Mineralized Nanoparticles: A Theranostic Agent for Ultrasound Imaging and Therapy of Cancers. ACS Nano, 2015. 9(1): p. 134-145.
36. Cheang, T.-y., et al., Calcium carbonate/CaIP6 nanocomposite particles as gene delivery vehicles for human vascular smooth muscle cells. Journal of Materials Chemistry, 2010. 20(37): p. 8050-8055.
37. Triplett, D.A., Coagulation and Bleeding Disorders: Review and Update. Clinical Chemistry, 2000. 46(8): p. 1260.
38. Palta, S., R. Saroa, and A. Palta, Overview of the coagulation system. Indian Journal of Anaesthesia, 2014. 58(5): p. 515-523.
39. Gale, A.J., Continuing Education Course #2: Current Understanding of Hemostasis. Toxicologic Pathology, 2011. 39(1): p. 273-280.
40. Jadali, A. and S. Ghazizadeh, Protein Kinase D Is Implicated in the Reversible Commitment to Differentiation in Primary Cultures of Mouse Keratinocytes. The Journal of Biological Chemistry, 2010. 285(30): p. 23387-23397.
41. Bikle, D.D., et al., Calcium- and vitamin D-regulated keratinocyte differentiation. Mol Cell Endocrinol, 2001. 177(1-2): p. 161-71.
42. Motta, G.J., Calcium alginate topical wound dressings: a new dimension in the cost-effective treatment for exudating dermal wounds and pressure sores. Ostomy Wound Manage, 1989. 25: p. 52-6.
43. Lansdown, A.B.G., Calcium: a potential central regulator in wound healing in the skin. Wound Repair and Regeneration, 2002. 10(5): p. 271-285.
44. Huang, J.-S., et al., Extracellular calcium stimulates DNA synthesis in synergism with zinc, insulin and insulin-like growth factor I in fibroblasts. European Journal of Biochemistry, 1999. 266(3): p. 943-951.
45. Pickering, S.U., CXCVI.-Emulsions. Journal of the Chemical Society, Transactions, 1907. 91(0): p. 2001-2021.
46. Ramsden, W., Separation of Solids in the Surface-Layers of Solutions and 'Suspensions' (Observations on Surface-Membranes, Bubbles, Emulsions, and Mechanical Coagulation). -- Preliminary Account. Proceedings of the Royal Society of London, 1903. 72(477-486): p. 156-164.
47. Binks, B.P., Particles as surfactants—similarities and differences. Current Opinion in Colloid & Interface Science, 2002. 7(1): p. 21-41.
48. Pieranski, P., Two-Dimensional Interfacial Colloidal Crystals. Physical Review Letters, 1980. 45(7): p. 569-572.
49. Binks, B.P. and S.O. Lumsdon, Influence of Particle Wettability on the Type and Stability of Surfactant-Free Emulsions. Langmuir, 2000. 16(23): p. 8622-8631.
50. 易成林, 杨., 江金强, 刘晓亚, 江明, 颗粒乳化剂的研究及应用. 化学进展, 2011. 23(01): p. 65-79.