Chitosan microparticles as entrapment system for trans- cinnamaldehyde: Synthesis, drug loading, and in vitro cytotoxicity evaluation

The ionic gelation method was used to study the effect of the crosslinking agent, sodium tripolyphosphate on average particle size (Dp) and zeta potential (ζp) of chitosan microparticles (CSMP) unloaded and loaded with trans-cinnamaldehyde (TCIN). The obtained values of Dp and ζp trend as 117.6 ± 0.4 ≤ Dp ≤ 478.5 ± 3.5 nm and +27.8 ± 1.3 ≤ ζp ≤ +103.5 ± 4.2 mV, respectively. The entrapment efficiency of TCIN in CSMP was 9.1 ± 2.0% and 71.5 ± 2.9% was released after 360 min (pH = 6.5) which reveals a potential anti-cancer activity in acidic environment. Cytotoxicity of TCIN in DMSO (0–50 μM) was evaluated on MDCK and HeLa cell lines and exhibited low effect at either 24 or 48 h of exposure; whereas TCIN-loaded CSMP (0–50 μM) showed, after 24 h of exposure, 67.6 ± 7.0 and 64.5 ± 3.9% cytotoxicity for MDCK and HeLa cell lines, respectively. At 48 h of exposure, TCIN-loaded CSMP achieved 81.1 ± 0.26 and 77.9 ± 4.2% cytotoxicity for MDCK and HeLa cell lines, respectively.