Experimental Study Of The Alginate-Chitosan-Alginate (ACA) Encapsulated Bovine Chromaffin Cells For Chronic Pain

A great deal of diseases and iinjures go with pains. According toWTO ,there are about 22% people suffering from pain all of the world.Pain ,especially chronic pain and terminate oncologic pain ,not onlyinfluences the life quality of the patientsseverly ,but also heavily burdensthe families and the society.The treatments there days for chronic pain havea lot of shortages and can,t satisfactorily cute it.Cell-transplantation foreasing pains is a new therapy that can solve the problem of theunsatisfactory cur effect. But it has to settle two matters before applying toclinic :one is limitations in donor availability, another is theimmuno-injection from the acceptors. Objective: Adopting a new technique, namely immunoisolution ,weencapsulated the homogeneity or heterogeneity cells ,and then transplantedthem into organism. After that ,we observed the transplanted cellsand theiranalgesic effecte.A lot of studies have revealed adrenal medullarychromaffin cells can secrete substance of analgesic effect.The bovineadrenal medullary most often serves as a sourse of these cells (BCCs)because of the large amount and relative availability of this tissue.Weadepoted natural polymers to make alginate-chitosan-alginate(ACA)microcapsules , which have fine intension and biocompatibility.TheBCCs were ACA encapsulated.We used the analgesic tests on the animalmodeis of chronic pain to evaluate the analgesia of BCCs andimmunoprotection effect of ACA microcapsules. Methods:1. Collagenase perfusion digestion ,mechanical dissociationand discontinuous density gradient centrifugation on Percoll have beenused to get BCCs with high purity and livability. 2. The functionalspecificities of BCCs in vitro was observed with tyrosine hydroxylase(TH)immunocytochemicao dyeingand we mensurated catecholamine levelof BCCs. 3. Electrostatic droplet technique was adopted to fabricate ACAmicrocapsules and BCCs were microencapsulated. Repeating meathod2,we observed morphological and functional specificities of themicroencapsulated BCCs. 4.We transplanted different grafts into the spinalsubarachnoid space fo 36 CCI SD rats (10 for ACA-BCCs ,10 for nakedBCCs ,8 for hollow ACA,and ,8 for normal solution ).We checked thechanges of all dynia and hyperalgesia of CCI SD rats aftertransplantationevery week to assayed the analgisic effect of BCCs and theability of ACAmicrocapsules to prevent immune reaction. Results:1. Collagenase perfusion digestion ,mechanical dissociationand discontinuous density gradient centrifugation on Percoll have beenused to get purified BCCs. Under the optimized conditios ,0.7～3.1×108cells could be islated pe adrenal gland with 99%viability and more than95%purity. 2.The obtained BCCs and the microencapsulated BCCs alsocould compose and secret catecholamine .3. The microencapsulated BCCsinduce analgesiaof CCI rat models. Furthermore ,under theimmunoprotection of ACA,BCCs kept alive and functional efficiently till 8weeks after tansplantation. Conclusion: 1. Collagenase perfusion digestion ,mechanicaldissociation and discontinuous density gradient centrifugation on Percollcould been used to get BCCs with high purity and livability. 2. Bycomparing the results of cell viability and functional activity of BCCs invitro ,the results proved that the BCCs could secret analgesic substancesuch as catecholamine ,and the time to transplantthe microencapsulatedBCCs was two to three days after isolation. 3.The material and prosess tomake ACAmicrocapsules did not do harm to the functional activity ofBCCs. 4.The analgisic effects of BCCs transplantation into the spinalarachnoid space were studid and the results proved thatmicroencapsulated BCCs produced remarkable analgesic effects.,and thatunder the immunoprotection of ACA ,the analgesia persist until eight weeksafter transplantation.