Investigation Of The In-vivo Photodynamic Therapy Unite Intra-articular Injection On Osteoarthritis Rabbit Model

Osteoarthritis is a common chronic bone and joint diseases which involve cartilage and subchondral bone.It is a complex process of occurrence and development of OA,probably relate to the age,genetic,trauma and unbalanced physiological process caused by inflammatory factors.The main clinical features include recurrent joint pain,swelling,and gradually increase,joint deformity,activity disorders.In three of the most common diseases of the world,prevalence and clinical case of OA are in the first place.OA prevalence in 60-70 years old elderly men are about 60%,the elderly over the age of 70,OA prevalence are about 70%.Joint cartilage loss is the main pathological changes.There is not any blood vessels,lymph and innervation exist in adults’ articular cartilage,articular cartilage cell proliferation ability is also very weak.It is difficult to repair itself,once the articular cartilage get damaged.This fact brings the great difficulties for the treatment of osteoarthritis.Photodynamic therapy damage diseased tissue mainly through direct,indirect damage and damage pannus of these three channels,and also combines the characteristics of highly effective,minimally invasive,low cost simultaneously.Photodynamic therapy will become a new direction in the field of osteoarthritis treatment.In this article,we elaborate the experimental study of photodynamic therapy(PDT)on osteoarthritis rabbit model.The main research content is as follows:1.Using improved-Hulth method make osteoarthritis mode.We have designed the experiment scheme with interval irradiation unite anticular injection of photosensitizer,and randomly divided the animals into three treatment groups according to the different photosensitizer dose(2 mg,4 mg,8 mg).After completion of treatment,we have analyzed the change of organization form of articular cartilage and cartilage metabolite levels.It was found that:photodynamic therapy could reduce the level of serum CTX-Ⅱand raise the level of the OC,and could also recovered structure and articular cartilage chondrocytes at the same time,new blood vessels-killing effect is obvious.This prompted the photodynamic therapy has a positive effect on osteoarthritis cartilage repair.2.To avoid the wastage of the tissue,body fluids,and the skin for laser,we use optical fiber and medullo-puncture needle(or a syringe needle)to design the experimental method of the in-vivo photodynamic therapy,and compare the effects of in-vivo PDT and in-vitro PDT,then consult the Mankin score and made quantitative data of cartilage tissue form to analyses the changes of articular cartilage organization form and cartilage metabolite levels.We found that in-vivo PDT and in-vitro PDT can reduce the serum CTX-Ⅱ,COMP,YKL-40 levels,repair cartilage structure,and in-vivo PDT is superior to the effect of in-vitro PDT in case of the same photosensitizer dose and light dose.This Fully Shows That,for osteoarthritis,in-vivo PDT can achieve a better therapeutic effect in the same conditions.