Poly(ε-caprolactone)-Banded Spherulites and Interaction with MC3T3-E1 Cells

Abstract

We report that protein adsorption, cell attachment, and cell proliferation were enhanced on spherulites-roughened polymer surfaces. Banded spherulites with concentric alternating succession of ridges and valleys were observed on spin-coated thin films of poly(ε-caprolactone) (PCL) and two series of PCL binary homoblends composed of high- and low-molecular-weight components when they were isothermally crystallized at 25-52 °C. Their thermal properties, crystallization kinetics, and surface morphology were examined. The melting temperature (T(m)), crystallinity (χ(c)), crystallization rate, and spherulitic patterns showed strong dependence on the crystallization temperature (T(c)) and the blend composition. The surface roughness of the spherulites was higher when T(c) was higher; thus, the larger surface area formed in banded spherulites could adsorb more serum proteins from cell culture media. In vitro mouse preosteoblastic MC3T3-E1 cell attachment, proliferation, and nuclear localization were assessed on the hot-compressed flat disks and spherulites-roughened films of the high-molecular-weight PCL and one of its homoblends. The number of attached MC3T3-E1 cells and the proliferation rate were greater on the rougher surfaces than those on the flat ones. It is interesting to note that cell nuclei were preferentially, though not absolutely, located in or close to the valleys of the banded spherulites. The percentage of cell nuclei in the valleys was higher than 78% when the ridge height and adjacent ridge distance were ~350 and ~35 nm, respectively. This preference was weaker when the ridge height was lower or at a higher cell density. These results suggest that isothermal crystallization of semicrystalline polymers can be an effective thermal treatment method to achieve controllable surface roughness and pattern for regulating cell behaviors in tissue-engineering applications.

Biomimetic Calcium Carbonate Concentric Microgrooves with Tunable Widths for Promoting MC3T3‐E1 Cell Functions

“…The present results can be compared with our recent reports on two groups of substrates with concentric microgrooves 13, 40. Consistently, photo‐crosslinked PCLTA substrates with highly uniform 7.5‐μm‐wide and 10‐μm‐deep concentric grooves enhanced MC3T3‐E1 cell alignment and mineralization; however, different microgroove dimensions did not influence cell attachment and proliferation in that study and no groove width smaller than 7.5 μm was used 13.…”

“…Cell alignment was less significant when the aspect ratio of grooves, defined by dividing the groove depth by the width, was smaller, because cells cannot sense the shallow surface topography efficiently 46. For MC3T3‐E1 cells seeded on poly(ϵ‐caprolactone) banded spherulites with the groove depth of ∼350 nm and the groove width of ∼30 μm, cell attachment and proliferation were better than those on flat hot‐compressed disks but no cell alignment was observed because of the low aspect ratio of grooves 40. In another report, focal conic structures with 700‐nm‐high ridges spaced ∼8.5 μm apart were found on the solvent cast films of cholesteryl oligo(L‐lactic acid) and 3T3 fibroblasts could survive and proliferate better on these self‐assembled domains and spread preferentially along the domain boundaries but not along the concentric rings 47.…”

Porous three-dimensional carbon nanotube scaffolds for tissue engineering

“…Since the 3D macroporous MWCNT and SWCNT scaffolds could be utilized as implants for bone tissue engineering applications, they will primarily interact with precursor osteoblasts cells in vivo . Thus, MC3T3 cells, a widely accepted cell line for in vitro bone studies were utilized as model cell lines to evaluate the in vitro cytocompatibility of MWCNT and SWCNT scaffolds [56]. …”

“…Thus, MC3T3 cells, a widely accepted cell line for in vitro bone studies were utilized as model cell lines to evaluate the in vitro cytocompatibility of MWCNT and SWCNT scaffolds. 56 To quantitatively assess the cytotoxicity of MWCNT and SWCNT scaffolds, we performed LDH assay to assess cell death of MC3T3 cells after 1, 3, and 5 days of culture. Porous PLGA scaffolds were used as live controls.…”

In vitrocytocompatibility of one-dimensional and two-dimensional nanostructure-reinforced biodegradable polymeric nanocomposites

“…The loading concentration of each nanomaterial was the concentration that showed maximum reinforcement of PPF polymer in our previous studies [16, 17]. The adherent NIH3T3 fibroblast-like cells [46, 47] and MC3T3 osteoblast precursor cells [48, 49] used in this study are widely accepted for in vitro cytotoxicity testing of materials of orthopedic or bone tissue engineering applications. In vitro cytotoxicity studies were performed before crosslinking, after crosslinking, and after accelerated degradation of the nanocomposites.…”