RESUMO
We have developed a technique to create 50µm-deep microwells coated with a reactive and robust thin film, which withstands photolithographic processing, and allows for subsequent chemical functionalisation with biological cues (i.e. peptides). First, plasma polymerisation of 1-bromopropane was used to generate a bromine-functionalised thin film (BrPP) on a substrate of silicon wafer. Second, an epoxy functionalised polymer UV photoresist, SU-8, was deposited and developed to create 50µm-deep patterned microwells that display the BrPP coating at their base. Third, amino acids or peptides were selectively attached to the bottom of the microwells through bromine displacement by an amine or thiol nucleophile. Each surface functionalisation step was monitored by XPS, AFM, and contact angle measurements. These functionalities were then used as linkers to immobilise enzymes (e.g. HRP), which retain activity at the end of the process as shown by a biochemical activity assay. Peptide promoters of cell attachment were also immobilised and their functionality was evaluated using an L929 fibroblast adhesion assay. In conclusion, this work describes an innovative combination of plasma thin film deposition and photolithography to create 50µm-deep functionalised microwells for peptide display in biological applications.
Assuntos
Materiais Revestidos Biocompatíveis/química , Compostos de Epóxi/química , Peptídeos/química , Polímeros/química , Análise Serial de Proteínas/instrumentação , Silício/química , Adesão Celular/efeitos dos fármacos , Linhagem Celular , Materiais Revestidos Biocompatíveis/farmacologia , Enzimas Imobilizadas/química , Fibroblastos/efeitos dos fármacos , Peroxidase do Rábano Silvestre/química , Hidrocarbonetos Bromados/química , Microscopia de Força Atômica , Processos Fotoquímicos , Espectroscopia Fotoeletrônica , Análise Serial de Proteínas/métodos , Propriedades de SuperfícieRESUMO
Micropatterning of surfaces with varying chemical, physical and topographical properties usually requires a number of fabrication steps. Herein, we describe a micropatterning technique based on plasma enhanced chemical vapour deposition (PECVD) that deposits both protein resistant and protein repellent surface chemistries in a single step. The resulting multifunctional, selective surface chemistries are capable of spatially controlled protein adhesion, geometric confinement of cells and the site specific confinement of enzyme mediated peptide self-assembly.
