Conformal Encapsulation of Three-Dimensional, Bioresorbable Polymeric Scaffolds Using Plasma-Enhanced Chemical Vapor Deposition

Abstract

Bioresorbable polymers such as poly(ε-caprolactone) (PCL) have a multitude of potential biomaterial applications such as controlled-release drug delivery and regenerative tissue engineering. For such biological applications, the fabrication of porous three-dimensional bioresorbable materials with tunable surface chemistry is critical to maximize their surface-to-volume ratio, mimic the extracellular matrix, and increase drug-loading capacity. Here, two different fluorocarbon (FC) precursors (octofluoropropane (C3F8) and hexafluoropropylene oxide (HFPO)) were used to deposit FC films on PCL scaffolds using plasma-enhanced chemical vapor deposition (PECVD). These two coating systems were chosen with the intent of modifying the scaffold surfaces to be bio-nonreactive while maintaining desirable bulk properties of the scaffold. X-ray photoelectron spectroscopy showed high-CF2 content films were deposited on both the exterior and interior of PCL scaffolds and that deposition behavior is PECVD system specific. Scanning electron microscopy data confirmed that FC film deposition yielded conformal rather than blanket coatings as the porous scaffold structure was maintained after plasma treatment. Treated scaffolds seeded with human dermal fibroblasts (HDF) demonstrate that the cells do not attach after 72 h and that the scaffolds are noncytotoxic to HDF. This work demonstrates conformal FC coatings can be deposited on 3D polymeric scaffolds using PECVD to fabricate 3D bio-nonreactive materials.

Rapid and Complete Surface Modification with Strain‐Promoted Oxidation‐Controlled Cyclooctyne‐1,2‐Quinone Cycloaddition (SPOCQ)

“…S3 surfaces showed three bands centered at 285.0 (C−C), 286.9 (C−O and C−N), and 289.0 eV (C=O), in accordance with the presence of an immobilized 1,2‐quinone group on the surface (Figure 2 A) 12a. After the SPOCQ reaction with derivative 1 , the peak deconvolution also showed components corresponding to the fluorinated tag (Figure 2 B), such as a −CF 3 peak centered at 294.3 eV and a larger peak from −CF 2 − at 291.6 eV 12b. M11/6‐311+G(d,p)‐derived simulated C1s XPS spectra agreed well with the experimental spectra (Supporting Information, Figure S6) 12c…”

Innovative Applications of Surface Wettability Measurements for Plasma‐Modified Three‐Dimensional Porous Polymeric Materials: A Review

“…Using two different plasma treatments, a CW 1,7‐octadiene system and a pulsed C 3 F 8 system, we have created surfaces that are nominally more hydrophobic than the untreated materials, where C 3 F 8 plasma treatment creates the most hydrophobic surfaces. For 1,7‐octadiene treatments, plasma modification occurs via hydrocarbon‐rich film deposition, whereas C 3 F 8 plasma treatment deposits a fluorocarbon film . Regardless of substrate identity, advancing CA values are greater than receding CAs as expected.…”

“…Unfortunately, it is unclear how the percentage of OC functional groups was calculated, as the fitting parameters of high‐resolution spectra were not included. In our work on fluorocarbon plasma‐modified PCL scaffolds, we observed an increase in WCA after plasma treatment, and attributed it to an increase in carbon/fluorine functionality as measured by elemental analysis obtained from high‐resolution XPS spectra . In both studies, the material architectures remain largely unchanged, as evidenced by SEM analysis.…”

“…PCL scaffolds were fabricated using the porogen leaching method, previously outlined . Briefly, PCL pellets (Sigma–Aldrich, average M n = 80 000) were dissolved in CHCl 3 (Fisher Scientific, ≥99.8%) and as received sodium chloride (NaCl, Sigma–Aldrich, ≥99%), sieved to a specific dimension (particle size 150–300 µm) was added to the dissolved PCL/CHCl 3 mixture (5/95% w/w PCL/NaCl) as the porogen and the mixture cast into Teflon molds (10 × 3 mm 2 wells or 20 × 3 mm 2 wells).…”

Thin film deposition at atmospheric pressure using dielectric barrier discharges: Advances on three-dimensional porous substrates and functional coatings

“…Several treatment strategies have been developed so far. For instance, gas phase techniques, [42][43][44][45][46][47][48] liquid phase reactions 49) as well as dip-, spin-, and spray-coating methods [50][51][52][53] have been reported for thin film deposition on a large variety of complex porous materials, such as polymer, metal, and ceramic foams or scaffolds. The low pressure PECVD has been successfully utilized for thin film deposition onto the outer and inner surfaces of 3D porous materials, without affecting their bulk properties and porous architecture.…”