An understanding of potential and limitations of alginate/PLL microcapsules as a cell retention system for perfusion cultures

Abstract

Microcapsules for high cell density culture of mammalian cells have found an increasing interest, however, the poor stability of the microcapsules and the lack of characterisation methods led to few quantitative results. Alginate-poly-L-lysine (PLL) microcapsules have been studied in detail in order to form a basis for comparison of capsules made from different polymers. Since the microcapsules can be easily retained in the bioreactor without the need for a cell separation device, high cell densities were achieved with a maximum of 4 × 10(7) cell/ml(microcapsules), corresponding to a colonisation of 5% of the internal capsule volume. Measurement of microcapsule integrity and mechanical resistance showed that alginate-PLL microcapsules are not suitable for perfusion cultures since they are very sensitive to media composition, mainly the presence of non-gelling ions that have a higher affinity for alginate than PLL and Ca(2+), leading to the leakage of PLL and Ca(2+), and to microcapsule rupture.

Efficacy of the incorporation between self-encapsulation and cryoprotectants on improving the freeze-dried survival of probiotic bacteria

“…As discussed, microencapsulation not only improves the freeze‐dried viability loss of probiotics, but also protects them from the harsh environmental conditions of the gastrointestinal tract during consumption (Cook et al, 2012). However, if only with protectants, there may be certain limitations such as the broken instability of the microencapsulation (Demont et al, 2016). Meanwhile, EPSs form a biofilm matrix around the cell (Nazir et al, 2019; Whitfield et al, 2015), firmly bound to the cell wall providing effective protection.…”

Hydrogel Biomaterials for Stem Cell Microencapsulation

“…They found that the encapsulated WJMSCs produced secretomes (e.g., interleukins, chemokines, growth factors, and soluble forms of adhesive molecules) [37]. Alginate microgels are often coated with polycationic polymers, such as poly- l -lysine (PLL), to enhance the membrane integrity [57]. Although alginate has been fundamentally easy to use for stem cell microencapsulation, alginate does not present biologically active moieties.…”

Co-Microencapsulation of BMSCs and Mouse Pancreatic (3 Cells for Improving the Efficacy of Type I Diabetes Therapy

“…The characteristics of alginate-polylysine-alginate (APA) microcapsules have been discussed previously (28,29). Murua (24) reported that when a high-voltage electrostatic method was used, the cells in APA microcapsules maintained good viability.…”