Background: There is a significant interest in effective oral drug delivery of therapeutic substances.
For probiotics, there is a particular need for a delivery platform that protects the bacteria from destruction by the
acidic stomach while enabling targeted delivery to the intestine where microbiota naturally reside. The use of
probiotics and how they impact the gut microbiota is a growing field and holds promise for the treatment of a
variety of gastrointestinal diseases, including irritable bowel disease Crohn’s disease and C. diff and other diseases,
such as obesity, diabetes, Parkinson’s, and Alzheimer’s diseases.
Objective: The aim of this research was to use our newly developed chemically-modified alginate hydrogel with
the characteristic feature of stability in acidic environments but disintegration under neutral-basic pH conditions
to design a novel system for effective targeted delivery of ingested probiotics.
Methods and Results: We have used the approach of encapsulation of bacterial cells in the hydrogel of the modified
alginate with in vitro studies in both simulated stomach acid and intestinal fluid conditions to demonstrate the
potential application of this novel platform in oral delivery of probiotics. Our data provide a proof-of-concept that
enables further studies in vivo with this delivery platform.
Conclusion: We have demonstrated in the present study that our chemically modified alginate hydrogel is resistant
to acidic conditions and protects bacterial cells encapsulated in it, but it is sensitive to neutral-basic pH conditions
under which it disintegrates and releases its viable bacteria cell payload. Our data provide a proof-ofconcept
that enables further studies in vivo with this delivery platform for the efficacy of therapeutic bacteria in
various disease conditions.