Construction Of Functional Polymer Interface And Their Applications In Life Analysis

As a multi-disciplinary research direction, constructing the function interface haspenetrated in various field. Especially the interface sensing and its applications have attractedmore and more attention. Among construct functional polymer interface and biologicalapplications is the focus of current research. Mainly due to the properties of the polymer canbe artificial adjusted by different chemical reactions for the different objects. At present,many polymers have been used to construct functional interfaces for different biologicalapplications. However, the inherent shortcomings of these materials, such as surface inert, theviability of interface cell and nonspecific adsorption, serious constraint their furtherapplications in life analysis field. We found that synthesizing the new materials andconstructing the function interface was the key to solve this problem. Therefore, the maincontent of the present study was preparation of functional polymers and their applications inbiology. According to our present results, the conclusions were made as follows.1. In this study, a new type of acetylcholine-like biomimetic polymers for their potentialin biomaterial-modulated nerve regeneration application is synthesized using click chemistryand free radical polymerization. The structure of the synthesized polymers includes a“bioactive” unit (acetylcholine-like unit) and a “bioinert” unit [poly(ethylene glycol) unit]. Toexplore the effects of the bioactive unit and the bioinert unit on neuronal growth, differentratios of the two initial monomers poly(ethylene glycol) monomethyl ether-glycidylmethacrylate (MePEG-GMA) and dimethylaminoethyl methacrylate (DMAEMA) wereemployed and five different polymers were synthesized. Their chemical structures werecharacterized using1H nuclear magnetic resonance (1H NMR) and Fourier-transform infraredspectroscopy (FT-IR), and their physical properties (including molecular weight,polydispersity, glass transition temperature, and melting point) were determined using gelpermeation chromatography (GPC) and differential scanning calorimetry (DSC). Culturing ofthe primary rat hippocampal neurons on the polymeric surfaces show that the ratio of the twoinitial monomers utilized for polymer synthesis significantly affects neuronal growth. Rathippocampal neurons show different growth morphologies on different polymeric surfaces.The polymeric surface prepared with1:60(mol/mol) of MePEG-GMA to DMAEMA induces neuronal regenerative responses similar to that on poly-L-lysine, a very common benchmarkmaterial for nerve cell cultures. These results suggest that acetylcholine-like biomimeticpolymers are potential biomaterials for neural engineering applications, particularly inmodulating the growth of hippocampal neurons.2. A quaternized poly(dimethylaminoethyl methacrylate)-grafted poly(dimethylsiloxane)(PDMS) surface (PDMS-QPDMAEMA) was successfully prepared in this study viasolution-phase oxidation reaction and surface-initiated atom transfer radical polymerization(SI-ATRP) using dimethylaminoethyl methacrylate (DMAEMA) as initial monomer. PDMSsubstrates were first oxidized in H2SO4/H2O2solution to transform the Si-CH3groups on theirsurfaces into Si-OH groups. Subsequently, a surface initiator for ATRP was immobilized ontothe PDMS surface, and DMAEMA was then grafted onto the PDMS surface viacopper-mediated ATRP. Finally, the tertiary amino groups of PolyDMAEMA (PDMAEMA)were quaternized by ethyl bromide to provide a cationic polymer brush-modified PDMSsurface. Various characterization techniques, including contact angle measurements,attenuated total reflection infrared spectroscopy (ATR-FT-IR), and X-ray photoelectronspectroscopy (XPS), were used to ascertain the successful grafting of the quaternizedPDMAEMA brush onto the PDMS surface. Furthermore, the wettability and stability of thePDMS-QPDMAEMA surface were examined by contact angle measurements. Antifoulingproperties were investigated via protein adsorption, as well as bacterial and cell adhesionstudies. The results suggest that the PDMS-QPDMAEMA surface exhibited durablewettability and stability, as well as significant antifouling properties, compared with thenative PDMS and PDMS-PDMAEMA surfaces. In addition, our results present possible usesfor the PDMS-QPDMAEMA surface as adhesion barriers and antifouling or functionalsurfaces in PDMS microfluidics-based biomedical applications.3. A new antifouling polyester monomethoxy-poly(ethylene glycol)-b-poly(l-lactide)-b-poly(sulfobetaine methacrylate)(MPEG-PLA-PSBMA) was obtained by ring-openingpolymerization of L-lactide, and subsequent click chemistry to graft the azideend-functionalized poly(sulfobetaine methacrylate)(polySBMA) moieties onto the alkyneend-functionalized MPEG-PLA (MPEG-PLA-alkyne). The chemical structure of the polymerwas characterized using1H nuclear magnetic resonance (1H NMR) and Fourier-transforminfrared spectroscopy (FT-IR), and its physical properties (including molecular weight, glasstransition temperature, and melting point) were determined using gel permeationchromatography (GPC) and differential scanning calorimetry (DSC). To investigate itshydrophilicity and stability, as well as its antifouling properties, the polymer was alsoprepared as a surface coating on glass substrates. The wettability and stability of this polyester was examined by contact angle measurements. Furthermore, its antifouling properties wereinvestigated via protein adsorption, cell adhesion studies, and bacterial attachment assays. Theresults suggest that the prepared zwitterionic polyester exhibits durable wettability andstability, as well as significant antifouling properties. The new zwitterionic polyesterMPEG-PLA-PSBMA could be developed as a promising antifouling material with extensivebiomedical applications.4. In this study, we prepared four new polyesters: poly(sulfobetaine methacrylate)-,poly(2-methacryloyloxyethyl phosphotidylcholine)-, poly(ethylene glycol)-, and quaternizedpoly[(2-dimethylamino)ethyl methacrylate]-grafted poly(propargyl glycolide)-co-poly(ε-caprolactone). The synthesis was conducted through ring-opening polymerization ofacetylene-functionalized lactones and grafting using click chemistry. The chemical structuresof the polyesters were characterized through nuclear magnetic resonance (1H NMR) andFourier-transform infrared spectroscopy (FT-IR), and their physical properties (includingmolecular weight, glass transition temperature, and melting point) were determined using gelpermeation chromatography (GPC) and differential scanning calorimetry (DSC). For studieson their hydrophilicity, stability, and anti-bioadhesive property, a series of polymeric surfacesof these polyesters was prepared by coating them onto glass substrates. The hydrophilicityand stability of these polyester surfaces were examined by contact angle measurements andattenuated total reflection Fourier-transform infrared spectroscopy (ATR-FT-IR). Theiranti-bioadhesive property was investigated through protein adsorption, as well as cellular andbacterial adhesion assays. The prepared polyesters showed good hydrophilicity andlong-lasting stability, as well as significant anti-fouling property. Thus, the newly preparedpolyesters could be developed as promising anti-fouling materials with extensive biomedicalapplications.In conclusion, in the present study we have successfully synthesized a series of polymerswith different biological function, constructed a series of poymer interface, and explored theirapplication in the life analysis. The study was carried out for different biological functionpolymers preparation methods and techniques, the properties of biological function polymersand its biological applications in-depth study of the system. At the same time, it analysis anddiscuss the further application of these polymers in the biomedical field.