Osteoblasts with impaired spreading capacity benefit from the positive charges of plasma polymerised allylamine

Abstract

Bone diseases such as osteoporosis, osteoarthritis and rheumatoid arthritis, impinge on the performance of orthopaedic implants by impairing bone regeneration. For this reason, the development of effective surface modifications supporting the ingrowth of implants in morbid bone tissue is essential. Our study is designed to elucidate if cells with restricted cell-function limiting adhesion processes benefit from plasma polymer deposition on titanium. We used the actin filament disrupting agent cytochalasin D (CD) as an experimental model for cells with impaired actin cytoskeleton. Indeed, the cell's capacity to adhere and spread was drastically reduced due to shortened actin filaments and vinculin contacts that were smaller. The coating of titanium with a positively charged nanolayer of plasma polymerised allylamine (PPAAm) abrogated these disadvantages in cell adhesion and the CD-treated osteoblasts were able to spread significantly. Interestingly, PPAAm increased spreading by causing enhanced vinculin number and contact length, but without significantly reorganising actin filaments. PPAAm with the monomer allylamine was deposited in a microwave-excited low-pressure plasma-processing reactor. Cell physiology was monitored by flow cytometry and confocal laser scanning microscopy, and the length and number of actin filaments was quantified by mathematical image processing. We showed that biomaterial surface modification with PPAAm could be beneficial even for osteoblasts with impaired cytoskeleton components. These insights into in vitro conditions may be used for the evaluation of future strategies to design implants for morbid bone tissue.

A quantitative method to analyse F-actin distribution in cells

“…Lastly, our method can be done with freely available software and we have developed a fully automated pipeline, from image to final analysis. Other researchers have looked at characterizing individual actin stress fibers, or different actin structures within cell, but not distribution [[4], [5], [6], [7]].…”

Plasma Polymerized Allylamine—The Unique Cell-Attractive Nanolayer for Dental Implant Materials

“…PPAAm was deposited on smooth and rough surfaces like polished, machined, or corundum-blasted titanium (Ti) [15] or titanium alloy [13,19], electrospun polylactide fiber meshes [14], β-tricalcium phosphate scaffolds [12], as well as a µm-thick, porous calcium phosphate layer [11]. The final plasma process conditions were chosen so as to yield substrate surfaces completely covered by a thin (>20 nm) PPAAm plasma polymer film.…”

Copper as an alternative antimicrobial coating for implants - an in vitro study

“…The cell adhesion of MG-63 osteoblasts on the different material surfaces was determined as already described[39]. Briefly, suspended MG-63 cells in DMEM with 10% FCS (5 × 10 4 cells/0.3 mL) were seeded directly onto sample discs.…”