Cell Encapsulation Within Alginate Microcapsules: Immunological Challenges and Outlook

Cell encapsulation is a bioengineering technology that provides live allogeneic or xenogeneic cells packaged in a semipermeable immune-isolating membrane for therapeutic applications. The concept of cell encapsulation was first proposed almost nine decades ago, however, and despite its potential, the technology has yet to deliver its promise. The few clinical trials based on cell encapsulation have not led to any licensed therapies. Progress in the field has been slow, in part due to the complexity of the technology, but also because of the difficulties encountered when trying to prevent the immune responses generated by the various microcapsule components, namely the polymer, the encapsulated cells, the therapeutic transgenes and the DNA vectors used to genetically engineer encapsulated cells. While the immune responses induced by polymers such as alginate can be minimized using highly purified materials, the need to cope with the immunogenicity of encapsulated cells is increasingly seen as key in preventing the immune rejection of microcapsules. The encapsulated cells are recognized by the host immune cells through a bidirectional exchange of immune mediators, which induce both the adaptive and innate immune responses against the engrafted capsules. The potential strategies to cope with the immunogenicity of encapsulated cells include the selective diffusion restriction of immune mediators through capsule pores and more recently inclusion in microcapsules of immune modulators such as CXCL12. Combining these strategies with the use of well-characterized cell lines harboring the immunomodulatory properties of stem cells should encourage the incorporation of cell encapsulation technology in state-of-the-art drug development

Novel organometallic compounds for cancer treatment

Incorporating indole, resorcinol, and porphyrin derivatives into ferrocene and ruthenium complexes could improve their anticancer activity. These compounds are furnished with functional groups which are expected to induce programmed cell death and show high selectivity to cancer cells. Currently, they are at the stage of in vitro testing for anticancer activity

Novel organometallic compounds for cancer treatment

Incorporating indole, resorcinol, and porphyrin derivatives into ferrocene and ruthenium complexes could improve their anticancer activity. These compounds are furnished with functional groups which are expected to induce programmed cell death and show high selectivity to cancer cells. Currently, they are at the stage of in vitro testing for anticancer activity

Rational design of new chemical drugs based on compounds that block the pores in cell membranes

“Rational Drug Design” method is a new principle and methodology in producing pharmaceuticals based on precise and structure-oriented approach. The proposed method is based on principle of blocking the pores caused by Staphylococccus aureus (S. aureus) toxins in the membranes of host cells [1]. Design of β-cyclodextrin derivatives with precise geometry might be used for production of antibacterial and prophylactic pharmaceuticals against S. aureus infection