Alginate-chitosan (AC) microencapsulated cell culture was carried out with S.cerevisiae BY4741 (yeast cells) as cell model.By controlling the same membrane formation time or the same membrane thickness of AC microcapsules

the effects of chitosan molecular weight (Mw) on membrane swelling behavior

microencapsulated cell growth and cell leakage from microcapsules were investigated.When keeping the same membrane formation time

the smaller the chitosan Mw

the easier the molecules diffusing into alginate network

resulting in thicker membrane with the ability of resisting swelling.However

when keeping the same membrane thickness

chitosan with larger Mw could provide more binding sites on the surface of alginate network

resulting in more compact membrane with the ability of resisting swelling.Furthermore

all kinds of AC microencapsulated cells prepared with different chitosan Mw by keeping the same membrane formation time and membrane thickness were cultured for 48 h.The growth dynamics of AC microencapsulated yeast cells were investigated.It showed that AC microcapsules prepared with smaller chitosan Mw at sufficient membrane formation time demonstrated higher membrane strength

but the cell growth was lower due to the thicker membrane that occupied more space of microcapsules and increased transfer resistance.It was also noticed that there was almost no cells leakage during the process of microencapsulated cell culture in all experiments.