Investigation on PEG Integrated Alginate–Chitosan Microcapsules for Myocardial Therapy Using Marrow Stem Cells Genetically Modified by Recombinant Baculovirus

Abstract

Bone marrow derived mesenchymal stem cell (BMSCs) therapy can significantly improve cardiac ventricular function following ischemic injury. Their potential can be further enhanced by using genetically modified cells, overexpressing certain therapeutic biomolecules. However, such therapy is limited by low efficiency of transplantation of the cells, secreting inadequate therapeutic proteins. To address these issues, we developed recombinant baculoviruses to genetically modify the BMSCs and investigated the potential of using polyethylene glycol (PEG) integrated alginate-chitosan microcapsules (AC) for efficient myocardial transplantation. The data indicates that the cells encapsulated in AC-PEG microcapsules grew rapidly from 80 cells per capsule to above 100 cells per capsule within a week, reaching a confluency of average 110 cells by day 9 of encapsulation. The microcapsules proved superior to commonly used AC microcapsules in terms of immune protection. After 11 days of co-culture of the encapsulated cells with highly confluent lymphocytes, the viable cell population in AC-PEG microcapsules was reduced by only 20%, whereas in AC microcapsules it was reduced to more than 50%. AC-PEG microcapsules also had significantly higher mechanical (65 vs. 10%) and osmotic (92 vs. 52%) stability than commonly used AC microcapsules as seen after 2 h of external stresses. The entrapped genetically modified cells showed highest transgene expression on day 1, which was gradually reduced to 48% after 1 week and to 14% after 2 weeks. This expression pattern was also dependant on initial viral incubation time, with 8 h incubation being the optimum. The encapsulated cells, transduced with baculovirus, also retained their inherent potential to differentiate into multiple lineages. Because of the above characteristics, the baculovirus transduced microencapsulated BMSCs have immense potential in myocardial cell-based gene therapy, although preclinical studies are needed to be done to establish their functional benefits on myocardial implantation.

Bone Marrow Stem Cell Derived Paracrine Factors for Regenerative Medicine: Current Perspectives and Therapeutic Potential

“…Hence, current research is highly focused on developing an efficient delivery system that can successfully transplant a sufficient number of stem cells at the desired site with higher retention and minimal biological loss or immune response. Some of our more recent work has shown that retention can be increased by four folds in the heart by using biocompatible polymeric alginate microcapsules as a delivery system, which can, in turn, help in functional recovery of acutely infarcted heart [ 59 – 61 ].…”

BacMam Virus Transduced Cardiomyoblasts Can Be Used for Myocardial Transplantation Using AP-PEG-A Microcapsules: Molecular Cloning, Preparation, andIn VitroAnalysis

“…An improper coating can make the capsular surface charged. Hydrophilic, nonionic, and the inert nature of PEG make it an ideal candidate to neutralize the surface charge and hence increase the immunoprotective potential of the capsules by alleviating the chance of having surface protein adhesions [ 19 , 50 ].…”

“…Artificial cell microencapsulation, a concept in which biologically active materials are encapsulated in specialized ultrathin semipermeable polymer membranes, has been proposed here as means to address the above-mentioned problem [ 17 – 19 ]. These microcapsules provide a large surface area to volume ratio which promotes rapid diffusion of oxygen, nutrients, and waste metabolites.…”

Superior Therapeutic Potential of Young Bone Marrow Mesenchymal Stem Cells by Direct Intramyocardial Delivery in Aged Recipients with Acute Myocardial Infarction: In Vitro and In Vivo Investigation

“…To induce differentiation, young and old MSCs were first seeded in 24-well plates at a high confluency using serum supplemented DMEM media. After 24 hours of culture, the media were replaced with either osteogenesis induction media or adipogenesis induction media (Millipore, Billerica, MA) to induce differentiation [ 15 , 16 ]. During this period, the induction media were replaced every alternate day with fresh induction media and later, differentiation media according to the manufacturer's protocol.…”