Purpose: The aim of the present study was to evaluate the use of the nonresorbable vinyl styrene microbeads (VSM) alloplast as a delivery vehicle for platelet-derived growth factor (PDGF-BB) in rat calvarial critical size defects.
Materials And Methods: Seventy-three Long-Evans male rats were divided into 4 groups; a negative control, vinyl styrene microbeads (VSM), PDGF-BB, and VSM plus PDGF-BB. Critical size calvarial defects were carried out and isolated with membranes sandwiching the defects with their fillers. Animals were sacrificed after 2, 4, and 16 weeks classifying each group into 3 subgroups. Calvarial specimens were radiographed for evaluation of regenerated bone volume and densitometry histogram analysis. Specimens were divided mid-sagittally and stained with hematoxylin and eosin (H&E) and trichrome stain for qualitative and histomorphometric analysis using an image analysis software.
Results: The VSM groups showed statistically higher defect fills than the VSM-free groups at all sacrifice times except for the VSM/PDGF group that showed this difference after 2 weeks in relation to the PDGF group and the negative control after 4 and 16 weeks. For the radiographic analysis, the VSM/PDGF group showed the lowest bone volume compared with the other groups except when it was compared with the 4 weeks VSM group. In contrast, the PDGF showed the highest bone volumes at all sacrifice times that were only significant when compared with the 4 weeks VSM group and the 4 and 16 weeks VSM/PDGF group.
Conclusions: VSM enhances bone defect fill whereas the VSM/PDGF-BB is not able to improve bone regeneration capacity when compared with VSM alone.
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http://dx.doi.org/10.1016/j.joms.2006.10.039 | DOI Listing |
J Am Chem Soc
January 2025
Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States.
Poly(vinyl chloride) (PVC) and polystyrene (PS) are among the least recycled plastics. In this work, we developed a simple and novel strategy to valorize PVC and PS plastics via photothermal conversion to (1-chloroethyl)benzene, a commodity chemical with excellent versatility. As PVC is known to release HCl gas and decompose into conjugated polyenes, we envisioned a dual role for PVC plastics.
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December 2024
Syensqo, Centre de Recherche et Innovation Aubervilliers, 52 Rue de la Haie Coq, 93308 Aubervilliers Cedex, France.
Rhodixan A1 is the trade name for -ethyl -(1-methoxycarbonylethyl)dithiocarbonate, a RAFT/MADIX agent used by Syensqo to produce block copolymer additives for aqueous formulations on an industrial scale. Chain transfer coefficients to Rhodixan A1 determined for 25 different styrenic, acrylate, and acrylamide monomers were relatively low (0.6 < C < 3.
View Article and Find Full Text PDFJ Org Chem
January 2025
Department of Chemistry, Malaviya National Institute of Technology Jaipur, Jaipur 302017, Rajasthan, India.
Int J Biol Macromol
December 2024
Graduate Program in Chemistry, Federal University of Alfenas, Alfenas, MG 37130-001, Brazil; Institute of Chemistry, Federal University of Alfenas, Alfenas, MG 37130-001, Brazil. Electronic address:
The objective of this study was to produce new and renewable bio-based plasticizers from used soybean cooking oil (USCO). First, USCO was completely converted into free fatty acids (FFAs) using lipase from Candida rugosa. Next, these FFAs were enzymatically esterified with benzyl alcohol in solvent-free systems.
View Article and Find Full Text PDFChemistry
December 2024
Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
Two-dimensional (2D) polymer network monolayers with novel block architectures were fabricated via sequential copolymerization within a pillared-layer metal-organic framework (MOF) that served as the reaction template. The MOF provides a confined 2D nanospace, restricting the crosslinking copolymerization of vinyl monomers to two dimensions. Sequential crosslinking copolymerization of methyl methacrylate and styrene, regulated by the reversible addition-fragmentation chain transfer (RAFT) process, resulted in the formation of 2D block architectures with 'patchy' domains consisting of crosslinked poly(methyl methacrylate) and polystyrene segments.
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