Bone is an important part of the human body and is composed of periosteum, bone and bone marrow. Normal bones are always in the dynamic equilibrium of bone formation and bone resorption in bone reconstruction, and they coordinate with each other to maintain the physiological functions of bones. If the pathological change occurs during normal bone reconstruction, various bone diseases such as osteoporosis, deformity osteitis, bone metastases, primary and secondary bone tumors, and osteoarthritis will occur. Due to the high hardness, poor permeability, and special physiological and biochemical processes of the bone tissue, it is difficult for the general route of administration to transport the drug to the lesion site.…

Physiological characteristics of lymph The lymphatic system consists of lymphatic channels, lymphoid organs, and lymphoid tissues. Colorless and transparent lymph fluid flows in the lymph system. Lymphatic vessels include capillary lymphatic vessels, lymphatic vessels, and lymphatic ducts. Lymphatic organs include lymph nodes, thymus, and spleen. When blood flows through the capillaries, part of the liquid substance seeps into the interstitial space, forming interstitial fluid. Most are absorbed into the blood through the venous ends of the capillaries, and a small part of the water content and the interstitial fluid of macromolecules enter the capillary lymphatic vessels to become lymph. The lymph flows to the heart along the lymph vessels at…