Glycerol Monomethacrylate Research Articles

PH-responsive non-ionic diblock copolymers: ionization of carboxylic acid end-groups induces an order-order morphological transition.

A carboxylic acid based reversible additionfragmentation transfer (RAFT) agent is used to prepare gels composed of worm-like diblock copolymers using two non-ionic monomers, glycerol monomethacrylate (GMA) and 2-hydroxypropyl methacrylate (HPMA). Ionization of the carboxylic acid end-group on the PGMA stabilizer block induces a worm-to-sphere transition, which in turn causes immediate degelation. This morphological transition is fully reversible as determined by TEM and rheology studies and occurs because of a subtle change in the packing parameter for the copolymer chains. A control experiment where the methyl ester derivative of the RAFT agent is used to prepare the same diblock copolymer confirms that no pH-responsive behavior occurs in this case. This end-group ionization approach is important for the design of new pH-responsive copolymer nano-objects as, unlike polyacids or polybases, only a minimal amount of added base (or acid) is required to drive the morphological transition.

PH‐Responsive Non‐Ionic Diblock Copolymers: Ionization of Carboxylic Acid End‐Groups Induces an Order–Order Morphological Transition

AbstractA carboxylic acid based reversible additionfragmentation transfer (RAFT) agent is used to prepare gels composed of worm‐like diblock copolymers using two non‐ionic monomers, glycerol monomethacrylate (GMA) and 2‐hydroxypropyl methacrylate (HPMA). Ionization of the carboxylic acid end‐group on the PGMA stabilizer block induces a worm‐to‐sphere transition, which in turn causes immediate degelation. This morphological transition is fully reversible as determined by TEM and rheology studies and occurs because of a subtle change in the packing parameter for the copolymer chains. A control experiment where the methyl ester derivative of the RAFT agent is used to prepare the same diblock copolymer confirms that no pH‐responsive behavior occurs in this case. This end‐group ionization approach is important for the design of new pH‐responsive copolymer nano‐objects as, unlike polyacids or polybases, only a minimal amount of added base (or acid) is required to drive the morphological transition.

Cisplatin-loaded polymer/magnetite composite nanoparticles as multifunctional therapeutic nanomedicine

Multifunctional nanocarriers with multilayer core-shell architecture were prepared by coating superparamagnetic Fe3O4 nanoparticles with diblock copolymer folate-poly(ethylene glycol)-b-poly(glycerol monomethacrylate) (FA-PEG-b-PGMA), and triblock copolymer methoxy poly(ethylene glycol)-b-poly(2-(dimethylamino) ethyl methacrylate)-b-poly(glycerol monomethacrylate) (MPEG-b-PDMA-b-PGMA). The PGMA segment was attached to the surfaces of Fe3O4 nanoparticles, and the outer PEG shell imparted biocompatibility. In addition, folate was conjugated onto the surfaces of the nanocarriers. Cisplatin was then loaded into the nanocarrier by coordination between the Pt atom in cisplatin and the amine groups in the inner shell of the multilayer architecture. The loaded cisplatin showed pH-responsive release: slower release at pH 7.4 (i.e. mimicking the blood environment) and faster release at more acidic pH (i.e. mimicking endosome/lysosome conditions). All of the cisplatin-loaded nanoparticles showed concentration-dependent cytotoxicity in HeLa cells. However, the folate-conjugated cisplatin-loaded carriers exhibited higher cytotoxicity in HeLa cells than non-folate conjugated cisplatin-loaded carriers.

An orthogonal click-chemistry approach to design poly(glycerol monomethacrylate)-based nanomaterials for controlled immunostimulation.

A versatile approach is proposed for the synthesis of novel immunoactive nanomaterials based on biocompatible poly(glycerol monomethacrylate) (PGMMA). Propargyl-terminated PGMMA is synthesized via atom transfer radical polymerization and then modified through the introduction of dangling acrylate groups, at controlled degree of functionalisation. Acrylates are then able to react quantitatively with thiols, such as immunoactive thiomannose, through Michael-type addition under mild conditions and at a physiologically acceptable pH. The terminal propargyl group can be modified independently with azide end-capping groups and it is utilized to graft the macromolecules to a fluorescent dye. The resulting mannose-linked PGMMAs confirm a safe cytotoxic profile and are able to stimulate cytokine production (TNFα), membrane protein expression (CD40), and cellular uptake in bone marrow derived dendritic cells. Cell stimulation is dependent on the mannose content and enhanced by serum proteins, suggesting a role for mannose-binding receptors and/or complement receptors in the cell membrane.

Poly(glycerol monomethacrylate)–Poly(benzyl methacrylate) Diblock Copolymer Nanoparticles via RAFT Emulsion Polymerization: Synthesis, Characterization, and Interfacial Activity

A poly(glycerol monomethacrylate) (PGMA) macromolecular chain transfer agent has been utilized to polymerize benzyl methacrylate (BzMA) via reversible addition–fragmentation chain transfer (RAFT)-mediated aqueous emulsion polymerization. This formulation leads to the efficient formation of spherical diblock copolymer nanoparticles at up to 50% solids. The degree of polymerization (DP) of the core-forming PBzMA block has been systematically varied to control the mean particle diameter from 20 to 193 nm. Conversions of more than 99% were achieved for PGMA51–PBzMA250 within 6 h at 70 °C using macro-CTA/initiator molar ratios ranging from 3.0 to 10.0. DMF GPC analyses confirmed that relatively low polydispersities (Mw/Mn < 1.30) and high blocking efficiencies could be achieved. These spherical nanoparticles are stable to both freeze–thaw cycles and the presence of added salt (up to 0.25 M MgSO4). Three sets of PGMA51–PBzMAx spherical nanoparticles have been used to prepare stable Pickering emulsions at variou...

Preparation of surface-imprinted polymer grafted with water-compatible external layer via RAFT precipitation polymerization for highly selective and sensitive electrochemical determination of brucine

A novel brucine imprinted polymer was prepared on multi-walled carbon nanotubes by reversible addition–fragmentation chain transfer (RAFT) precipitation polymerization. The polymer was further grafted with hydrophilic poly(glycerol monomethacrylate) brushes to improve its water-compatibility. The obtained molecularly imprinted material showed enhanced accessibility to brucine and improved selective recognition property in water medium. When the material was supported on an ionic liquid functionalized graphene coated glassy carbon electrode for the electrochemical determination of brucine, the resulting electrochemical sensor presented good analytical performance. Under the optimized conditions, the peak current was linear to brucine concentration in the ranges of 0.006−0.6μM and 0.6−5.0μM with sensitivities of 15.3μA/μMmm2 and 5.4μA/μM mm2, respectively; the detection limit was 2nM (S/N=3). The sensor was successfully applied to the determination of brucine in practical samples and the recovery for the standards added was 94−104%.

Amine functional hydrogels as selective substrates for corneal epithelialization

The aim of this study was to develop a synthetic hydrogel to act as a corneal substitute capable of selectively supporting the adhesion and proliferation of limbal epithelial cells (LECs) while inhibiting growth of limbal fibroblasts. Deficiency of LECs causes conjunctival epithelial cells to move over the cornea, producing a thick scar pannus. Unilateral defects can be treated using LEC cultured from the unaffected eye, transplanting them to the affected cornea after scar tissue is removed. The underlying wound bed is often damaged, however, hence the need to develop a corneal inlay to aid in corneal re-epithelialization. Transparent epoxy-functional polymethacrylate networks were synthesized using a combination of glycerol monomethacrylate, ethylene glycol dimethacrylate, lauryl methacrylate and glycidyl methacrylate that produced two different bulk hydrogel compositions with different equilibrium water contents (EWCs): Base 1 and Base 2, EWC=55% and 35%, respectively. Two sets of amine-functional hydrogels were produced following reaction of the epoxide groups with excesses of either ammonia, 1,2-diamino ethane, 1,3-diamino propane, 1,4-diamino butane or 1,6-diamino hexane. Neither series of hydrogels supported the proliferation of limbal fibroblasts irrespective of amine functionalization but they both supported the adhesion and proliferation of limbal epithelial cells, particularly when functionalized with 1,4-diamino butane. With Base 1 hydrogels (less so with Base 2) a vigorous epithelial outgrowth was seen from small limbal explants and a confluent epithelial layer was achieved in vitro within 6days. The data support the development of hydrogels specific for epithelial formation.

Determination of melamine and cyromazine in milk by high performance liquid chromatography coupled with online solid-phase extraction using a novel cation-exchange restricted access material synthesized by surface initiated atom transfer radical polymerization

A novel strong-cation-exchange restricted access material has been synthesized by atom transfer radical polymerization (ATRP). In the synthesis, poly(3-sulfopropyl methacrylate-co-ethylene dimethacrylate), [p(SPM/EDMA)] was grafted on the silica by surface-initiated ATRP first. The poly(glycerol mono-methacrylate) [pGMMA] was then immobilized on the external surface, which created a chemical diffusion barrier for protein exclusion. The resulting Sil-g-p(SPM/EDMA)-g-pGMMA has both functions of protein exclusion and cation exchange, exhibiting the property of cation-exchange restricted access material. The application of Sil-g-p(SPM/EDMA)-g-pGMMA has been studied by the determination of melamine and cyromazine in bovine milk using the online solid-phase extraction/HPLC method. In the process, the Sil-g-p(SPM/EDMA)-g-pGMMA was used for the sample pre-treatment and a HILIC column was employed as the analytical column. The method has shown good accuracy, precision and low limits of detections. The result demonstrated that the Sil-g-p(SPM/EDMA)-g-pGMMA can be used for the cation extraction from biological samples by direct HPLC injection.

Enzymatically synthesized polyesters with pendent OH groups as macroinitiators for the preparation of well‐defined graft copolymers by atom transfer radical polymerization

A family of polyesters, poly(glycerol adipate) (PGA), poly(sorbitol adipate) and PGA‐graft‐poly(ε‐caprolactone), bearing OH groups on their backbones were synthesized by enzymatic polycondensation. They were successfully converted into macroinitiators for atom transfer radical polymerization (ATRP) by esterification with α‐bromoisobutyryl bromide. As a proof of concept, glycerol monomethacrylate was polymerized by ATRP from a PGA backbone yielding the amphiphilic graft copolymer PGA‐graft‐poly(glycerol monomethacrylate). Its self‐assembly in aqueous solution was studied using dynamic light scattering. © 2013 Society of Chemical Industry

Binding of amphiphilic and triphilic block copolymers to lipid model membranes: the role of perfluorinated moieties.

A novel class of symmetric amphi- and triphilic (hydrophilic, lipophilic, fluorophilic) block copolymers has been investigated with respect to their interactions with lipid membranes. The amphiphilic triblock copolymer has the structure PGMA(20)-PPO(34)-PGMA(20) (GP) and it becomes triphilic after attaching perfluoroalkyl moieties (F9) to either end which leads to F(9)-PGMA(20)-PPO(34)-PGMA(20)-F(9) (F-GP). The hydrophobic poly(propylene oxide) (PPO) block is sufficiently long to span a lipid bilayer. The poly(glycerol monomethacrylate) (PGMA) blocks have a high propensity for hydrogen bonding. The hydrophobic and lipophobic perfluoroalkyl moieties have the tendency to phase segregate in aqueous as well as in hydrocarbon environments. We performed differential scanning calorimetry (DSC) measurements on polymer bound lipid vesicles under systematic variation of the bilayer thickness, the nature of the lipid headgroup, and the polymer concentration. The vesicles were composed of phosphatidylcholines (DMPC, DPPC, DAPC, DSPC) or phosphatidylethanolamines (DMPE, DPPE, POPE). We showed that GP as well as F-GP binding have membrane stabilizing and destabilizing components. PPO and F9 blocks insert into the hydrophobic part of the membrane concomitantly with PGMA block adsorption to the lipid headgroup layer. The F9 chains act as additional membrane anchors. The insertion of the PPO blocks of both GP and F-GP could be proven by 2D-NOESY NMR spectroscopy. By fluorescence microscopy we show that F-GP binding increases the porosity of POPC giant unilamellar vesicles (GUVs), allowing the influx of water soluble dyes as well as the translocation of the complete triphilic polymer and its accumulation at the GUV surface. These results open a new route for the rational design of membrane systems with specific properties.

Surface modification of silicone via colloidal deposition of amphiphilic block copolymers

We report here on a method to functionalize silicone surfaces, which is based on the deposition of silicone-containing amphiphilic block copolymers from a colloidal water–ethanol dispersion. Using cross-linked silicones (Sylgard 184) as substrates, copolymers composed of two poly(glycerol monomethacrylate) (PGMMA) terminal blocks and a central poly(dimethylsiloxane) (PDMS) block can be effectively deposited when the PDMS content is ≥46 wt%. (≥65 mol%); the deposition provides smooth and stable surfaces, which significantly affected the protein adsorption behaviour of the substrate, suggesting a possible application in biomaterial coating. In air, the block copolymer surface films underwent a reorganization, which differs from the classical hydrophobic recovery of silicones and may be related to a disordered folding of lamellar structures. This led to a predominant surface coverage by thin, possibly monomolecular layers, which displayed a non-restructuring polar surface. However, as a consequence of the reorganization also larger aggregates were produced, albeit in relatively small numbers; these aggregates underwent a progressive hydrophobization (in this case a hydrophobic recovery) and probably dominated the contact angle behaviour of the material. In summary, the colloidal deposition of amphiphilic silicone-based block copolymers successfully modifies the surface properties of silicone substrates; however, attention must paid to reorganization phenomena in order to maximize the stability of the coating.

Aqueous worm gels can be reconstituted from freeze-dried diblock copolymer powder.

Worm-like diblock copolymer nanoparticles comprising poly(glycerol monomethacrylate) (PGMA) as a stabilizer block and poly(2-hydroxypropyl methacrylate) (PHPMA) as a core-forming block were readily synthesized at 10% w/w solids via aqueous dispersion polymerization at 70 °C using Reversible Addition-Fragmentation chain Transfer (RAFT) chemistry. On cooling to 20 °C, soft transparent free-standing gels are formed due to multiple inter-worm interactions. These aqueous PGMA-PHPMA diblock copolymer worms were freeze-dried, then redispersed in water with cooling to 3-5 °C before warming up to 20 °C; this protocol ensures molecular dissolution of the copolymer chains, which aids formation of a transparent aqueous gel. Rheology, SAXS and TEM studies confirm that such reconstituted gels comprise formed PGMA-PHPMA copolymer worms and they possess essentially the same physical properties determined for the original worm gels prior to freeze-drying. Such worm gel reconstitution is expected to be highly beneficial in the context of various biomedical applications, since it enables worm gels to be readily prepared using a wide range of cell growth media as the continuous aqueous phase.

Facile synthesis of thiol-functionalized amphiphilic polylactide–methacrylic diblock copolymers

Biodegradable amphiphilic diblock copolymers based on an aliphatic ester block and various hydrophilic methacrylic monomers were synthesized using a novel hydroxyl-functionalized trithiocarbonate-based chain transfer agent. One protocol involved the one-pot simultaneous ring-opening polymerization (ROP) of the biodegradable monomer (3S)-cis-3,6-dimethyl-1,4-dioxane-2,5-dione (L-lactide, LA) and reversible addition–fragmentation chain transfer (RAFT) polymerization of 2-(dimethylamino)ethyl methacrylate (DMA) or oligo(ethylene glycol) methacrylate (OEGMA) monomer, with 4-dimethylaminopyridine being used as the ROP catalyst and 2,2′-azobis(isobutyronitrile) as the initiator for the RAFT polymerization. Alternatively, a two-step protocol involving the initial polymerization of LA followed by the polymerization of DMA, glycerol monomethacrylate or 2-(methacryloyloxy)ethyl phosphorylcholine using 4,4′-azobis(4-cyanovaleric acid) as a RAFT initiator was also explored. Using a solvent switch processing step, these amphiphilic diblock copolymers self-assemble in dilute aqueous solution. Their self-assembly provides various copolymer morphologies depending on the block compositions, as judged by transmission electron microscopy and dynamic light scattering. Two novel disulfide-functionalized PLA-branched block copolymers were also synthesized using simultaneous ROP of LA and RAFT copolymerization of OEGMA or DMA with a disulfide-based dimethacrylate. The disulfide bonds were reductively cleaved using tributyl phosphine to generate reactive thiol groups. Thiol–ene chemistry was utilized for further derivatization with thiol-based biologically important molecules and heavy metals for tissue engineering or bioimaging applications, respectively.

From a Water-Immiscible Monomer to Block Copolymer Nano-Objects via a One-Pot RAFT Aqueous Dispersion Polymerization Formulation

We describe the facile atom-efficient synthesis of diblock copolymer nano-objects via a one-pot RAFT aqueous dispersion polymerization protocol starting from a water-immiscible methacrylic monomer. More specifically, an aqueous emulsion of glycidyl methacrylate (GlyMA) is quantitatively converted into a 10% w/w aqueous solution of glycerol monomethacrylate (GMA) at 80 °C in air within 9 h in deionized water. 1H NMR spectroscopy studies indicate no evidence for either methacrylic ester hydrolysis or polymerization during this ring-opening reaction. Kinetic analysis indicates that a significant rate acceleration occurs as the reaction mixture switches from a two-phase emulsion to a single aqueous phase. This observation is fully consistent with the GlyMA–GMA–water ternary phase diagram determined at 80 °C. The 10% w/w aqueous solution of GMA can be polymerized using RAFT chemistry to produce a near-monodisperse PGMA macromolecular chain-transfer agent (macro-CTA), which indicates that relatively little dime...

Combination of Episulfide Ring‐Opening Polymerization With ATRP for the Preparation of Amphiphilic Block Copolymers

We report for the first time the combination of ATRP and ring-opening episulfide polymerization as a means to synthesize polysulfide-based low-dispersity amphiphilic block copolymers. The most significant finding is the possibility to perform ATRP under mild conditions using poly(propylene sulfide) macroinitiators, apparently without any significant copper sequestration by the polysulfides. Using glycerol monomethacrylate (GMMA) as a hydrophilic monomer, the polymers self-assembled in colloidal structures with a morphology depending on the PS/GMMA ratio, but also probably on GMMA degree of polymerization. We here also present a new AFM-based method to calculate the average number of amphiphilic macromolecules per micelle.

Preparation of clenbuterol imprinted monolithic polymer with hydrophilic outer layers by reversible addition–fragmentation chain transfer radical polymerization and its application in the clenbuterol determination from human serum by on-line solid-phase extraction/HPLC analysis

A novel imprinted monolithic material with the ability of protein exclusion was developed for the selective extraction of clenbuterol (CLE) from biological samples by direct injection in the HPLC analysis. The material has an imprinted inner structure and hydrophilic outer layer. The reversible addition-fragmentation chain transfer (RAFT) polymerization was employed in the material preparation by a two-step procedure. In the first step, clenbuterol imprinted monolithic polymer was synthesized by combining the molecular imprinting and the RAFT polymerization techniques. The resulting monolithic polymer has a RAFT chain transfer agent (trithioester groups) in its structure, which was used to graft poly(glycerol mono-methacrylate) [pGMMA] in the second step by post-RAFT polymerization. The hydrophilic pGMMA layers grafted on the surface of the imprinted monolith created barriers for protein diffusion. More than 90% of bovine serum albumin can be excluded from the pGMMA coated monolithic column. Meanwhile the clenbuterol was retained selectively with a large retention factor. The result indicated that the column, denoted as RA-MIM, has both the merits of a molecularly imprinted polymer and restricted access material. By using RA-MIM as the solid-phase extraction pre-column, an on-line column-switching HPLC method for the determination of clenbuterol in human serum has been established and validated. The recoveries of clenbuterol from the serum were 87.3-96.9% in the spiked level 2-1000 ng mL(-1). Both good linearity (R = 0.999) and acceptable reproducibility (RSD < 7.0%) were obtained. The limit of detection and the limit of quantitation were 0.7 ng mL(-1) and 2.0 ng mL(-1) respectively, which is sensitive in terms of UV detection. The results have demonstrated that the RAFT polymerization can be used to synthesize bi-functional monolithic columns by using its living reaction property. The resulting RA-MIM in this research can be used for efficient clenbuterol determination by HPLC from biological samples.

Block copolymers in giant unilamellar vesicles with proteins or with phospholipids

Biocompatible, highly water-soluble, nonionic, amphiphilic block copolymers having different hydrophobic blocks and architectures, but similar molecular size and chemical nature of the hydrophilic blocks, were investigated to check for their ability to form hybrid giant unilamellar vesicles with proteins, and for their interactions with giant unilamellar phospholipid vesicles (GUV). PGM14-b-PPO34-b-PGM14 (PGM-PPO-PGM) consists of a poly(propylene oxide) middle block and outer poly(glycerol monomethacrylate) blocks. Ch-PEG32-b-IPG18 (Ch-PEG-IPG) and Ch-PEG30-b-hbPG17 (Ch-PEG-hbPG) have a linear poly(ethylene glycol) block, linked to a cholesterol end group and to a linear (IPG) or hyperbranched (hbPG) polyglycerol block. Fluorescently-labelled polymers were synthesised to image and analyse the self-assembling and interaction processes using confocal laser scanning microscopy (CLSM). By implementing a novel strategy for polymersomes formation the copolymers were found to spontaneously form giant unilamellar vesicles with proteins in aqueous solution. Furthermore, the investigation of the interaction of the block copolymers with different phospholipid GUVs provided detailed information about the structure-behaviour relationship. Additionally, it was found that these neutral copolymers are able to cross artificial and natural phospholipid membranes.

Cationic Polyelectrolyte-Stabilized Nanoparticles via RAFT Aqueous Dispersion Polymerization

We report the synthesis of cationic sterically stabilized diblock copolymer nanoparticles via polymerization-induced self-assembly (PISA) using a RAFT aqueous dispersion polymerization formulation. The cationic steric stabilizer is a macromolecular chain-transfer agent (macro-CTA) based on quaternized poly(2-(dimethylamino)ethyl methacrylate) (PQDMA), and the hydrophobic core-forming block is based on poly(2-hydroxypropyl methacrylate) (PHPMA). The effect of varying synthesis parameters such as the salt concentration, solids content, relative block composition, and cationic charge density has been studied. In the absence of salt, self-assembly is problematic because of the strong repulsion between the highly cationic PQDMA stabilizer chains. However, in the presence of salt this problem can be overcome by reducing the charge density within the coronal stabilizer layer by either (i) statistically copolymerizing QDMA monomer with a nonionic comonomer (e.g., glycerol monomethacrylate, GMA) or (ii) using a binary mixture of a PQDMA macro-CTA and a poly(glycerol monomethacrylate) (PGMA) macro-CTA. These cationic diblock copolymer nanoparticles were analyzed by (1)H NMR spectroscopy, dynamic light scattering (DLS), transmission electron microscopy (TEM), and aqueous electrophoresis. NMR studies suggest that the HPMA polymerization is complete within 2 h at 70 °C. Depending on the specific reaction conditions, either spherical, wormlike or vesicular nanoparticles can be prepared with tunable cationic surface charge.

Direct Observation of Giant Pickering Emulsion and Colloidosome Droplet Interaction and Stability

The interactions of two 2-mm pendant oil droplets grown in the presence of an aqueous solution of poly(glycerol monomethacrylate)-stabilized polystyrene latex particles was observed using a high-speed video camera. The coalescence behavior was monitored as a function of oil type (n-dodecane versus sunflower oil) and particle size (135 versus 902 nm), as well as in the presence and absence of an oil-soluble cross-linker [tolylene 2,4-diisocyanate-terminated poly(propylene glycol)]. The damping coefficient of the coalescing n-dodecane droplets was found to increase in the presence of the latex, demonstrating particle adsorption. Coalescence times increased when the oil phase was changed from n-dodecane to sunflower oil, because of the much higher viscosity of the latter oil. In addition, increasing the adsorbed particle size from 135 to 902 nm led to longer coalescence times because of the greater distance separating the oil droplets. Coalescence times observed in the presence of the larger 902-nm particles indicated that two different modes of contact can occur prior to a coalescence event (bilayer or bridging monolayer of particles in the film). Addition of an oil-soluble surface-active cross-linker to the sunflower oil phase to react with the hydroxy groups of the particle stabilizer reduced the interfacial elasticity and ultimately prevented coalescence after cross-linking for 20 min at 25 °C. Such giant colloidosomes can remain in contact for several hours without undergoing coalescence, which demonstrates their high stability. Furthermore, coalescence is prevented even if the cross-linker is present in only one of the pendant droplets. Finally, evidence for cross-linker diffusion from one pendant droplet to another was indicated by a visible filament connecting the two droplets upon retraction.

Advantages of Surface‐Initiated ATRP (SI‐ATRP) for the Functionalization of Electrospun Materials

Surface-initiated atom transfer radical polymerization (SI-ATRP) is successfully applied to electrospun constructs of poly(L-lactide). ATRP macroinitiators are adsorbed through polyelectrolyte complexation following the introduction of negative charges on the polyester surface through its blending with a six-armed carboxy-terminated oligolactide. SI-ATRP of glycerol monomethacrylate (GMMA) or 2-(N,N-diethylamino)ethyl methacrylate (DEAEMA) allows then to grow surface films with controllable thickness, and in this way also to control the wetting and interactions of the construct.