ABSTRACT
Microencapsulation is a technique that protects viable cells in semi-permeable membranes, which allow passage of essential molecules while stopping larger molecules, such as antibodies, involved in the death of transplanted cells. This allows the avoidance of immunosuppressive drugs. Several substances have been used for this purpose, and alginate is one of the most studied and validated. Alginate is extracted from algae present in African and Chilean coasts; different algae can be mixed in variable proportions to produce alginate with distinct characteristics. Commercial alginate evokes an inflammatory response that results in the death of transplanted cells. High purity alginate has already been developed to avoid this issue. There are several applications to this technique, as there are a large number of pathologies that result from the destruction or extraction of tissues, with the consequent loss of function (diabetes mellitus or post-surgical hypoparathyroidism, for example). Finally, there is an additional interest in alginate microencapsulation in this country, given that it can be easily obtained from national algae.
La microencapsulación es una técnica que protege células viables en membranas semi-permeables, que permite el paso de moléculas que son esenciales para la célula y a la vez impide el paso de otras, como los anticuerpos, involucradas en la destrucción celular. Esto permite evitar el uso de drogas inmunosupresoras. Variadas biomacromoléculas pueden ser utilizadas con este fin, siendo el alginato uno de los biopolímeros más validados y estudiados. El alginato es un polisacárido amónico formado por unidades acidas b-L-manurónicas y a-L-gulorónicas, extraído desde algas presentes en costas africanas y chilenas. Así, diferentes algas pueden ser mezcladas en proporciones variables para producir alginatos de distintas características. El alginato comercial produce una respuesta inflamatoria que causa la muerte de las células trasplantadas; ya se han desarrollado alginatos de alta pureza para evitar este problema. Existen varias aplicaciones para esta técnica, ya que existen diversas patologías caracterizadas por una pérdida de función por destrucción o extracción de tejido (por ejemplo, diabetes mellitus o hipoparatiroidismo post-quirúrgico). Esta técnica representa un especial interés en Chile, ya que el alginato puede ser obtenido fácilmente a partir de algas chilenas.
Subject(s)
Humans , Alginates/chemistry , Immunosuppression Therapy/methods , Cell- and Tissue-Based Therapy/methods , Cell Transplantation/methods , Cell Survival , Tissue Preservation/methods , Immunocompetence , Biocompatible Materials/chemistryABSTRACT
Purpose:To evaluate the effect of Auto-PBSCT combined with long-time low-dose interleukin-2 (after transplant) for increasing the rate of 5-year disease-free survival of lymphoid malignancies (ALL and NHL).Methods:U- sing chemotherapy combined with low dose G-CSF to mobilize peripheral blood stem cells,we carried out auto-PBSCT in lymphoid malignancies (7 cases CR_1 ALL、1 case CR_2 ALL、3 cases CR_1 NHL、5 cases refractory NHL).After transplant, 15 cases used low dose interleukin-2 at 5.10~5U/d for one year or longer.Results:7 cases CR_1 ALL are still alive,the aver- age disease-free survival is 73 months.Median disease-free survival is 51.5 months.2 of 3 cases CR_1 NHL are still alive. The 6 years disease-free survival in 10 cases CR_1 lymphoid malignancies(CR_1 NHL and CR_1 ALL) is 0.90?0.11,the aver- age disease-free survival is 66.8 months.In another PR (refractory) group of NHL and ALL (CR_2),3 years disease-free survival was 0.33?0.18,and average survival time was 20.66 months,but a chemotherapy-sensitive NHL is still alive (63 months),a case of lymphoblast cell NHL also survived for 46 months and died after relapse.Conclusions:Auto-PBSCT combined with long-turm low dose IL-2(after transplant) could effectively increase the rate of 5-year disease-free survival in CR_1 lymphoid malignancies(ALL and NHL).