Table 1.
Initial characterization of porous particles.
Five images were analyzed per formulation.
Fig 1.
Morphology of porous PLGA MPs.
SEM images of (A) non-porous PLGA MPs and porous MPs prepared using (B) gelatin, (C) SBC, and (D) PMPs as porogens. The spherical morphology and porous nature of PLGA-Gelatin, PLGA-SBC, and PLGA-PMPs can be clearly visualized.
Fig 2.
Physical characterization of porous PLGA MPs.
(A) Particle stability in 10% serum indicating that non-porous PLGA, PLGA-SBC, PLGA-Gelatin, and PLGA-PMPs maintained their diameter and granulometric properties for 3 days. (B) Degradation of porous PLGA MPs investigated at 37°C for 4 weeks. PLGA-Gelatin particles degraded 83% of their initial weight in 28 days while PLGA-SBC particles and PLGA-PMPs were reduced to 61% and 46% of their original weight, respectively. The data plotted in terms of average ± standard error obtained from samples size (n) of 3.
Fig 3.
Cellular adhesion onto porous MPs.
A549 cell attachment on uncoated and fibronectin-coated particles for 24 hours. Maximum cell attachment was observed at 250,000 cells/mg of particles cell density for (A) PLGA-SBC and (B) PLGA-gelatin particles. Cell attachment was saturated at 150,000 cells/mg density for (C) PLGA-PMPs. The data plotted in terms of average ± standard error obtained from samples size (n) of 4 (* represents p-value <0.05 w.r.t cell attachment on uncoated particles, + represents p- value <0.05 w.r.t cell attachment between different cell seeding densities).
Fig 4.
Cellular viability on porous MPs.
(A) Live/dead and DAPI stained particles after 1-day culture indicating that the A549 lung cancer cells could attach onto the fibronectin-coated particles within 24 hours and were viable (green = live, red = dead, Scale = 10 μm). (B) SEM images of cell attachment on PLGA-Gelatin, PLGA-SBC and PLGA-PMPs demonstrate that the cells were clearly seen attached onto the surface of the MPs (arrows).
Fig 5.
Cellular proliferation on porous MPs.
(A) A549 cell proliferation on fibronectin-coated particles up to 9 days, showing significantly higher cell growth on PLGA-SBC porous particles compared to the non-porous control particles and other porous particles (PLGA-Gelatin, and PLGA-PMPs. The data plotted in terms of average ± standard error obtained from samples size (n) of 4 (# represents p<0.05 w.r.t porous PLGA-Gelatin and PLGA-PMPs). (B) Live/Dead staining shows A549 lung cancer cells attached on porous PLGA MPs were viable for up to 9 days with minimal cell death. PLGA-PMPs and PLGA-Gelatin MPs showed cell death on day 9 (arrows); however, cells on PLGA-SBC MPs remained viable throughout the study (Scale = 10 μm).
Fig 6.
In vitro cancer drug screening.
Effectiveness of chemotherapeutic drug treatment on A549 2D monolayer grown on TCPS and porous PLGA particles was quantified using LDH assays. It was observed that cancer drugs reduced only ~20–30% of A549 growth on the particles compared to its 2D counterparts when treated with the same concentrations of drugs. The percentage of A549 cell death was calculated with respect to untreated cells (N/T) lysed with triton. Data was statistically significant (n = 3, *p<0.05) when compared between two models (2D vs. particles) for each treatment groups.