Chronic illnesses such as Alzheimer’s or Parkinson’s could be treated more effectively in the future, by means of the transplant of microencapsulated cells. The researcher from the University of the Basque Country (UPV/EHU) Dr Ainhoa Murua has presented a number of proposals for optimising this technique. Amongst other things, she put forward improvements that can make viable the transplant of cells from other species (xenotransplants) to human patient, which would resolve the problem caused by the habitual scarcity of human tissues for transplanting. Her PhD thesis is entitled Cell microencapsulation for therapeutic purposes: towards greater control over biocompatibility.
This research has inspired the group of the Faculty of Pharmacy of which Dr Murua is a member to publish six articles in high-impact journals. Outstanding amongst these articles is that entitled Xenogeneic transplantation of erythropoietin-secreting cells immobilized in microcapsules using transient immunosuppression, which was the front cover of the Journal of Controlled Release in 2009 and which gained the 9th Award from the Spanish Association of Pharmaceutical Law (ASEDEF) in the category of Innovation.
The immunosuppressor Tacrolimus
Microencapsulation of cells involves coating specific cells with various biomaterials, in such a way that they form microparticles. These secrete therapeutic proteins in a controlled and continuous manner inside the organism in which they have been implanted. They turn out to be highly beneficial in chronic illnesses which require to be treated with a frequent intake of medication.
In her thesis, Dr Murua increased the functionality of the xenotransplants: she managed to prevent immunological rejection that these normally cause, without the need to use chronic treatment to this end. The researcher has shown that the transient application of Tacrolimus immunosuppressant (habitually used to inhibit the immunological reaction that patients subjected to a transplant usually suffer) is a sufficient and effective measure. In this way, the possibility is opened up of using cells of other species to treat chronic patients using microencapsulation.
Moreover, during the research a system was designed for the secretion of therapeutic substances which expressly aims to avoid the side effects of the said immunosuppressant. This involves combining encapsulated cells with microparticles of the biodegradable polymer known as PLGA or poly(lactic-co-glycolic acid), the latter being loaded with dexamethasone (acting as an anti-inflammatory and immunosuppresant). According to the thesis, the said system will enable the enhancement of the viability and functioning of implanted cells.
Finally, Dr Murua also developed a solution for storing and conserving microencapsulation in the long term. Concretely, a protocol has been created for their freezing, in order to guarantee suitable conditions for the storage and preservation of the cells and enable an optimum interchange of inter-laboratory research material.