根據世界衛生組織2021年的報導(World Health Organization)，全球約有15億人患有不同程度的聽力損失，到了2050年甚至會增加到25億人。聽力障礙不僅影響日常生活，甚至會大幅提其他疾病產生的風險，然而內耳複雜的結構以及生理上的屏障都大幅增加了內耳治療的困難，在內耳的醫學領域中，一些環境壓力如噪音或是耳毒性藥物影響下，將會產生活性氧物質，這些活性氧物質會和脂質、蛋白質、DNA產生化學反應破壞其結構，造成毛細胞死亡。二甲雙胍(Metformin, Met)能夠降低活性氧物質的生成，因此具有修復毛細胞損傷之能力，儘管如此耳蝸血迷路屏障對於藥物輸送卻造成巨大的阻礙。耳蝸血迷路屏障(blood-labyrinth barrier)和血腦屏障(blood-brain barrier)有諸多相似之處，對於許多大小分子都具有阻隔的作用，然而在一些研究中證實耳蝸血迷路屏障和血腦屏障在藥物傳輸存在不同的機制。因此本論文製備二甲雙胍包覆含氧白蛋白微氣泡(MetOMB)，並經由超音波介導技術提升氧氣與藥物通過耳蝸血迷路屏障的效率以及治療內耳損傷。
研究結果中，MetOMB的包覆率為65.50±2.87 %，平均粒徑大小和表面電位依序為1887.42±44.42 nm、-0.66±0.29 mV，濃度儀中量測MetOMB濃度為9.56±1.67 (×108 bubbles/mL)，從打破效率以及透析袋模擬氧氣釋放實驗中可以確認超音波具有引發MetOMB的穴蝕效應並釋放氧氣；在細胞實驗中分別進行HEI-OC1細胞的生存率以及活性氧（ROS）測試。從結果中，超音波結合MetOMB之缺損細胞生存率相較於No treatment(OGD)組可提升12.18%，ROS抑制效果為14.39%；在動物實驗中，以小鼠顱骨模擬體外打破效率以及內耳氧分壓量測，可以確認MetOMB經由超音波誘發的穴蝕效應達到氧氣的釋放，從無注射組(Control)、單純注射MetOMB (MetOMB) 組和注射MetOMB並施打超音波 (MetOMB＋US) 組之曲線下面積(AUC)依序為117.80±96.10、764.40±85.20、1429.64±270.35 mmHg，並且在聽力測試中確認藥物的安全性和治療效果

According to a 2021 report by the World Health Organization (WHO), about 1.5 billion people worldwide suffer from varying degrees of hearing loss, and this number will even increase to 2.5 billion by 2050. Hearing impairment not only affects daily life, but also increases the risk of other diseases. However, the complex structure and physiological barriers of the inner ear increase the difficulty of inner ear treatment. In the medical field of the inner ear, some environmental pressures such as noise or ototoxic drugs, reactive oxygen species will be produced. These reactive oxygen species will chemically react with lipids, proteins, and DNA to destroy their structures, causing hair cell death. Metformin (Met) can reduce the production of reactive oxygen species and has the ability to repair hair cell damage. However, the cochlear blood-labyrinthine barrier poses a huge obstacle to drug delivery. The cochlear blood-labyrinth barrier (BLB) and the blood-brain barrier (BBB) have many similarities and have blocking effects on many large and small molecules. However, some studies have confirmed that the cochlear blood-labyrinth barrier and the blood-brain barrier exist different mechanisms in drug delivery. Therefore, this paper prepared metformin-coated oxygenated albumin microbubbles (MetOMB), and combined with ultrasound to improve the delivery efficiency of the cochlear blood-labyrinthine barrier and treat inner ear damage.
According to the research results, the encapsulated rate of MetOMB is 65.50±2.87 %, the average particle size and surface zeta potential are 1887.42±44.42nm and -0.66±0.29mV, and the concentration of MetOMB is 9.56 ± 1.67 (×108 bubbles/mL), it can be confirmed from the breaking efficiency and dialysis bag simulated oxygen release experiments that ultrasound can induce the cavitation effect of MetOMB and release oxygen. In the results of the in vitro cell experiments, the survival rate and reactive oxygen species (ROS) of HEI-OC1 cells were measured. In the results, the damaged cell survival rate of ultrasound combined with MetOMB was increased by 12.18% compared with the No treatment group, and the ROS inhibition effect was 14.39%. In small animal experiments, partial pressure measurement can confirm that MetOMB achieves oxygen release through the cavitation effect induced by ultrasound. The area below curve (AUC) of partial pressure in no injection group (Control), the MetOMB injection group alone (MetOMB), and the MetOMB injection combined with ultrasound group (MetOMB+US) was 117.80±96.10, 764.40±85.20, 1429.64±270.35 mmHg, respectively, the safety and therapeutic effect of this new platform were confirmed in the hearing test.

[1]. Hirose K, Hartsock JJ, Johnson S, Santi P, Salt AN. Systemic lipopolysaccharide compromises the blood-labyrinth barrier and increases entry of serum fluorescein into the perilymph. J Assoc Res Otolaryngol. 2014;15:707–719.
[2]. White HJ, Helwany M, Biknevicius AR, et al. Anatomy, Head and Neck, Ear Organ of Corti. [Updated 2023 Jan 14]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-.
[3]. Shi X. Cochlear pericyte responses to acoustic trauma and the involvement of hypoxia inducible factor-1alpha and vascular endothelial growth factor. Am J Pathol. 2009;174:1692–704.
[4]. Lin F.R., Metter E.J., O’Brien R.J., Resnick S.M., Zonderman A.B., Ferrucci L. Hearing loss and incident dementia. Arch. Neurol. 2011;68:214–220.
[5]. Timothy D. Griffiths,∗ Meher Lad, Sukhbinder Kumar, Emma Holmes, Bob McMurray, Eleanor A. Maguire, Alexander J. Billig, and William Sedley. How Can Hearing Loss Cause Dementia? Neuron. 2020 Nov 11; 108(3): 401–412.
[6]. Bony Labyrinth - an overview. Science Direct. [2021-02-27]
[7]. 余德新. 職業健康: 職業病及職業意外. Chinese University Press, 1991.
[8]. Mary P. Lee, Joerg Waldhaus,In vitro and in vivo models: What have we learnt about inner ear regeneration and treatment for hearing loss?,Molecular and Cellular Neuroscience, Volume 120,2022,103736,
[9]. Wilson WR, Byl FM, Laird N. The efficacy of steroids in the treatment of idiopathic sudden hearing loss. A double-blind clinical study. Arch Otolaryngol. 1980 Dec;106(12):772-6
[10]. Chadha S, Kamenov K, Cieza A. The world report on hearing, 2021. Bull World Health Organ. 2021 Apr 1;99(4):242-242A
[11]. R. Thalmann, T. Miyoshi, and I. Thalmann, "The influence of ischemia upon the energy reserves of inner ear tissues," The Laryngoscope, vol. 82, no. 12, pp. 2249-2272, 1972.
[12]. Tabuchi K, Nishimura B, Tanaka S, Hayashi K, Hirose Y, Hara A. Ischemia-reperfusion injury of the cochlea: pharmacological strategies for cochlear protection and implications of glutamate and reactive oxygen species. Curr Neuropharmacol. 2010 Jun;8(2):128-34
[13]. B. Ö . Ç akir et al., "Negative effect of immediate hyperbaric oxygen therapy in acute acoustic trauma," Otology & Neurotology, vol. 27, no. 4, pp. 478-483, 2006.
[14]. Schwander M, Kachar B, Müller U, The cell biology of hearing. J. Cell Biol 190, 9–20 (2010).
[15]. Rubel EW, Furrer SA, Stone JS, A brief history of hair cell regeneration research and speculations on the future. Hear. Res 297, 42–51 (2013).
[16]. Safety, Tolerability and Efficacy for CGF166 in Patients With Unilateral or Bilateral Severe-to-profound Hearing Loss ClinicalTrials.gov Identifier: NCT02132130
[17]. Grzybowska M, Bober J, Olszewska M. Metformin-mechanisms of action and use for the treatment of type 2 diabetes mellitus. Postepy Hig Med Dosw (Online) 2011; 65:277-85.
[18]. Berstein LM. Metformin in obesity, cancer and aging:addressing controversies. Aging (Albany NY) 2012; 4:320-9.
[19]. Wu MS, Johnston P, Sheu WH, et al. Effect of Metformin on carbohydrate and lipoprotein metabolism in NIDDM patients. Diabetes Care 1990; 13: 1-8.
[20]. Piwkowska A, Rogacka D, Jankowski M, Dominiczak MH,Stepinski JK, Angielski S. Metformin induces suppression of NAD(P)H oxidase activity in podocytes. Biochem Biophys Res Commun 2010; 393: 268-73.
[21]. Fischer, Janos. Analogue-based Drug Discovery II. John Wiley & Sons. 2010: 47–49 [2016-09-07]. ISBN 9783527632121.
[22]. McKee, Mitchell Bebel Stargrove, Jonathan Treasure, Dwight L. Herb, nutrient, and drug interactions : clinical implications and therapeutic strategies. St. Louis, Mo.: Mosby/Elsevier. 2008: 217 [2016-09-07]. ISBN 9780323029643.
[23]. hattacharya and Prajapati BG et al.,“A conceptual review on micro bubbles”, Biomed J Sci Tech Res,2017;1(2):353–359.
[24]. Muhammad Saad Khan and Jangsun Hwang et al.,“Oxygen-Carrying Micro/Nanobubbles: Composition, Synthesis Techniques and Potential Prospects in Photo-Triggered Theranostics”, Molecules, 2018 Sep; 23(9): 2210.
[25]. Wang, S., J.A. Hossack, and A.L. Klibanov, Targeting of microbubbles: contrast agents for ultrasound molecular imaging. Journal of drug targeting, 2018. 26(5-6): p. 420-434.
[26]. S. Tinkov, R. Bekeredjian, G. Winter, and C. Coester, "Microbubbles as ultrasound triggered drug carriers," Journal of pharmaceutical sciences, vol. 98, no. 6, pp. 1935-1961, 2009.
[27]. X. Zhu et al., "Ultrasound triggered image-guided drug delivery to inhibit vascular reconstruction via paclitaxel-loaded microbubbles," Scientific reports, vol. 6, no. 1, pp. 1-12, 2016.
[28]. 陳思嘉, "靶向超音波於血栓溶解之研究," 臺灣大學生醫電子與資訊學研究所學位論文, pp. 1-64, 2009.
[29]. S. M. Fix et al., "Oxygen microbubbles improve radiotherapy tumor control in a rat fibrosarcoma model–A preliminary study," PLoS One, vol. 13, no. 4, p. e0195667, 2018.
[30]. Swanson EJ, Borden MA. Injectable oxygen delivery based on protein-shelled microbubbles. Nano LIFE. 2010 1(3):215-218.
[31]. Ho YJ, Cheng HL, Liao LD, Lin YC, Tsai HC, Yeh CK. Oxygen-loaded microbubble-mediated sonoperfusion and oxygenation for neuroprotection after ischemic stroke reperfusion. Biomater Res. 2023 Jul 6;27(1):65.
[32]. Mason, T.J., et al., Application of ultrasound, in Emerging technologies for food processing. 2005, Elsevier. p. 323-351.
[33]. Leighton, T.G., What is ultrasound? Progress in biophysics and molecular biology, 2007. 93(1-3): p. 3-83.
[34]. Wang, T.-Y., et al., Ultrasound and microbubble guided drug delivery: mechanistic understanding and clinical implications. Current pharmaceutical biotechnology, 2013. 14(8): p. 743-752.
[35]. LightYear. (2010). Ultrasound range diagram. Available: https://commons.wikimedia.org/w/index.php?curid=10755419
[36]. I. Lentacker, S. C. De Smedt, and N. N. Sanders, "Drug loaded microbubble design for ultrasound triggered delivery," Soft Matter, vol. 5, no. 11, pp. 2161-2170, 2009.
[37]. 謝依峻, "組織背景抑制於諧波對比劑偵測," 碩士, 電機工程系, 國立臺灣科技大學, 台北市, 2008.
[38]. M. Tomizawa, F. Shinozaki, Y. Motoyoshi, T. Sugiyama, S. Yamamoto, and M. Sueishi, "Sonoporation: Gene transfer using ultrasound," World journal of methodology, vol. 3, no. 4, p. 39, 2013.
[39]. I. Lentacker, S. C. De Smedt, and N. N. Sanders, "Drug loaded microbubble design for ultrasound triggered delivery," Soft Matter, vol. 5, no. 11, pp. 2161-2170, 2009.
[40]. F. S. Foster, C. J. Pavlin, K. A. Harasiewicz, D. A. Christopher, and D. H. Turnbull, "Advances in ultrasound biomicroscopy," Ultrasound in medicine & biology, vol. 26, no. 1, pp. 1-27, 2000.
[41]. Yuhang Tian and Zhao Liu et al.,“New Aspects of Ultrasound-Mediated Targeted Delivery and Therapy for Cancer”, Int J Nanomedicine,2020 Jan 21; 15: 401–418.
[42]. Peruzzi, G., et al., Perspectives on cavitation enhanced endothelial layer permeability. Colloids and Surfaces B: Biointerfaces, 2018. 168: p. 83-93.
[43]. Trachootham D, Alexandre J, Huang P. Targeting cancer cells by ROS-mediated mechanisms: a radical therapeutic approach? Nat Rev Drug Discov. 2009 Jul;8(7):579-91. doi: 10.1038/nrd2803. Epub 2009 May 29. PMID: 19478820.
[44]. Andersen JK. Oxidative stress in neurodegeneration: cause or consequence? Nat Med. 2004 Jul;10 Suppl:S18-25.
[45]. Shukla V, Mishra SK, Pant HC. Oxidative stress in neurodegeneration. Adv Pharmacol Sci. 2011;2011:572634.
[46]. Paravicini TM, Touyz RM. Redox signaling in hypertension. Cardiovasc Res. 2006 Jul 15;71(2):247-58.
[47]. Haigis MC, Yankner BA. The aging stress response. Mol Cell. 2010 Oct 22;40(2):333-44.
[48]. Ishikawa K, Takenaga K, Akimoto M, Koshikawa N, Yamaguchi A, Imanishi H, Nakada K, Honma Y, Hayashi J. ROS-generating mitochondrial DNA mutations can regulate tumor cell metastasis. Science.
[49]. Ray PD, Huang BW, Tsuji Y. Reactive oxygen species (ROS) homeostasis and redox regulation in cellular signaling. Cell Signal. 2012 May;24(5):981-90.