• Classification of artificial organs
    • Bone/dental/joint replacements (limb, knee, hip, dental implants, etc.)
    • Soft/connective tissues (skins, cartilage, ligaments, tendons, muscles, blood vessels, etc.)
    • Sensory organs/tissues (nerves, eyes, ears, etc.)
    • Internal organs (heart, kidney, lungs, etc.)
  • Clinical application
    • joint cartilage degeneration关节软骨退变, osteoarthritis骨关节炎 (OA)
      • Primary Problem
        • Damaged cartilage leads to various forms of arthritis 关节炎
        • Osteoarthrites骨关节炎 20.7 million Americans 美国有2070万患者
      • Symptoms
        • hard, bony swelling of the joints 关节硬性骨性肿胀
        • gritty feeling 关节活动时伴摩擦感
        • Immobility 关节活动受限
      • Solution
        • Total Knee Replacement (TKR)
        • Nearly 250,000 Americans receive knee implants each year
        • Current TKR Design
          • Three Primary Components:
              1. Femoral Component
              1. Tibial Component
              1. Patellar Component
            • 图
          • Materials - Cobalt-chromium钴铬合金, Ti-6Al-4V Titanium Alloy 钛6铝4钒合金
          • Interface - Press fit压配固定, PMMA (polymethyl methacrylate, bone cement骨水泥)
      • Results
        • Stops or greatly reduces joint pain
        • Improves the strength of the leg
        • Increases quality of life and comfort
    • Bone cement 骨水泥
      • PMMA polymethyl methacrylate 聚甲基丙烯酸甲酯
      • Key limitations
        • Non-degradable, no regeneration 不可降解、无再生功能
        • excessive stiffness 硬度过高
        • abnormal spine mechanics 导致脊柱力学异常
        • associated risk of future vertebra fracture 增加未来椎体骨折的相关风险
      • eg.Percutaneous balloon kyphoplasty (PKP) 经皮穿刺球囊扩张椎体后凸成形术
        • Treatment to compression fracture of osteoporotic vertebra 骨质疏松性椎体压缩骨折的治疗方式
      • eg. hip implants
        • 图
    • Dental implants
      • Drilled and placed into the jawbone.
      • Bone augmentation骨增量手术 is required if the jawbone volume is not adequate
      • Dental implant post or abutment is usually screwed into the top of the dental implant
      • 牙种植体基台通常通过螺丝固定在牙种植体顶部
      • An artificial dental crown can be made to precisely fit onto the implant post
      • 可定制人工牙冠，使其精准适配种植体基台
      • 图
      • Osseointegration 骨整合
        • The holy grail in orthopedic/dental implant design
        • 骨科 / 牙科种植体设计中的核心目标
        • A fixture is osseointegrated if it provides a stable and apparently immobile support of prosthesis under functional loads, without pain, inflammation, or loosening.
        • 若种植体在功能负荷下，能为修复体提供稳定且无明显松动的支撑，且无疼痛、无炎症、无松动情况，则表明该种植体已实现骨整合
      • Two ways of implant anchorage 锚点
        • Mechanical
          • Topological features: thread螺纹, slots槽道 etc.
        • Bioactive
          • HA 羟基磷灰石 hydroxyapatite, component of bone and teeth
          • Rapid osseointegration骨整合速度快
            • Biointegration in 4 weeks, 90% of implant-bone contact at 10 months.
            • In contrast, Titanium only 50% implant-bone contact at 10 months
    • Artificial skins
      • 图
    • Ligament Injury - ACL Re-construction Surgery
      • Harvest of Ligament Replacement from donor site (Patellar Tendon髌腱)
      • Patellar tendon (top) and Achilles tendon (bottom) allografts 髌腱(上方)与跟腱(下方)同种异体移植物
      • Anterior cruciate ligament (ACL) reconstruction - Grafting of replacement into holes drilled into the femur & tibia 将替代移植物植入预先在股骨和胫骨上钻好的骨孔中
      • The graded structure of ligament to bone insertion site
    • Tissue engineered cartilage
      • Cartilage regeneration
        • Elastic cartilage 弹性软骨(ear, nose)
        • Fibro cartilage 纤维软骨(meniscus)
        • Articular cartilage 关节软骨(knee, hip)
      • Cells used
        • Chondrocytes 软骨细胞
        • Stem cells (chondrogenesis required需要诱导软骨形成)
      • Autologous chondrocyte implantation (ACI)自体软骨细胞移植

        • 从患者自身获取软骨细胞，经体外培养扩增后，再移植到受损软骨部位以实现修复
    • Artificial and tissue engineered blood vessel
      • 图
    • Tissue engineered nerves
      • Peripheral nerve system
      • Central nerve system
      • Biomaterial-guided neural regeneration
      • ECM-derived biomaterials for neural tissue repair
    • Ophthalmic眼科的 implants
      • Lens replacement with intraocular lens after cataract surgery白内障手术
      • Tissue engineered cornea and vitreous humour (vitreous body) 玻璃体
        • Artificial cornea
        • Artificial vitreous body
    • Cardiovascular implants
      • 图
    • Total artificial heart
      • They require surgery
      • They allow mobility - a battery support patient to be “untethered” for about two to three hours.
      • They can be unwieldy笨重的 - large size and uncomfortable
      • They carry risks - infection at the two hoses that go through the skin with opening
      • They are temporary - to buy time for transplant of a donor heart
      • 图
    • Artificial kidney
      • Kidneys filter some 140 litres of blood each day, leaving behind a litre or two of water and waste in the form of urine.
      • 肾脏每天约过滤 140 升血液，最终留下 1 至 2 升水分和代谢废物，以尿液形式排出体外
      • Currently dialysis machine is based on antiquated陈旧的 technology and is too bulky to be portable.
      • Miniaturization of dialysis machine into a portable device is highly desirable.
      • 将透析机微型化改造为便携式设备的需求极为迫切
      • Artificial kidney with biological components is the future.