Temperature swing adsorption of melamine on thermosensitive poly(<Emphasis Type="Italic">N</Emphasis>-isopropylacrylamide) cryogels

In the past few years, polymer-based adsorbents have been emerging as highly effective alternatives to activated carbons for pollutants removal and recovery from industrial effluents. In this article, novel thermosensitive poly(N-isopropylacrylamide) (PNIPAAm) cryogels adsorbents were directly prepared with N-isopropylacrylamide (NIPAAm) as a thermosensitive monomer and PEG-20,000 as a porogen at −12 °C by means of an in situ free-radical redox cryopolymerization. Subsequently, PNIPAAm cryogels were further employed to adsorb and desorb melamine through temperature swing adsorption (TSA) between 25 and 50 °C. The adsorption isotherms were correlated to Langmuir and Freundlich isotherm models. Moreover, the result indicated that the developed PNIPAAm cryogels adsorbents could be utilized effectively to concentrate melamine from aqueous solutions and spiked liquid milk. The cycle of the adsorption and desorption could be repeated without much loss of the melamine adsorbing ability.     

Temperature-sensitivity and cell biocompatibility of freeze-dried nanocomposite hydrogels incorporated with biodegradable PHBV

The structure, morphology, thermal behaviors and cytotoxicity of novel hydrogels, composed of poly(N-isopropylacrylamide)(PNIPAM) and biodegradable polyester poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) under nanoclay hectorite “Laponite XLG” severed as physical cross-linker, were characterized by X-ray diffraction, scanning electron microscopy, gravimetric method, differential scanning calorimetry, and cell culture experiments. It was found that, due to the introduction of hydrophobic PHBV, the homogeneity of interior pore in the pure PNIPAM nanocomposite hydrogel was disrupted, the transparency and swelling degree gradually decreased. Although the weight ratio between PHBV and NIPAM increased from 5 to 40 wt.%, the volume phase transition temperature (VPTTs) of hydrogel were not altered compared with the pure PNIPAM nanocomposite hydrogel. No matter what PHBV content, the PHBV/PNIPAM/Hectorite hydrogels always exhibit good stimuli-responsibility. In addition, human hepatoma cells(HepG2) adhesion and spreading on the surface of PHBV-based hydrogels was greatly improved than that of pure PNIPAM nanocomposite hydrogel at 37 °C due to the introduction of PHBV.     

The effect of salts and pH buffered solutions on the phase transition temperature and swelling of thermoresponsive pseudogels based on <Emphasis Type="Italic">N-</Emphasis>isopropylacrylamide

The temperature sensitive nature of poly(N-isopropylacrylamide) makes it an attractive candidate for controlled drug delivery devices. A series of temperature responsive poly (N-isopropylacrylamide)-polyvinyl pyrrolidinone random copolymers were produced by free radical polymerisation using 1-hydroxycyclohexylphenyketone as a UV-light sensitive initiator. The chemical structure of the xerogels was characterised by means of Fourier transform infrared spectroscopy (FTIR). The copolymers possess a lower critical solution temperature (LCST) in pure water, but the transition temperature may be affected by the addition of various cosolutes. The LCST of the pseudogels (physically crosslinked gels) was investigated in distilled water and a variety of salt and pH buffer solutions, using modulated differential scanning calorimetry (MDSC) and rheological analysis. The pH buffer solutions prepared mimic the variety of conditions encountered by drug delivery systems administered orally. The pH effects on the LCSTs of the temperature sensitive gels appear not obvious; while the salts used to prepare the pH buffer solutions have a more notable effect (‘salting out effect’) on the phase transition temperature. All swelling studies were carried out on the hydrogels at 37°C in distilled water, pH buffer 1.2 and pH buffer 6.8. The swelling/dissociation behaviour of the gels is found to be highly dependent on the pH buffer solution used, as the salts incorporated in preparing the pH buffer solutions lowers the phase transition of the copolymers to below the test temperature of 37°C, thus making them less soluble.     

The synthesis,swelling behaviour and rheological properties of chemically crosslinked thermosensitive copolymers based on <Emphasis Type="Italic">N</Emphasis>-isopropylacrylamide

In this contribution thermosensitive polymer matrices based on N-isopropylacrylamide have been developed. The hydrogels were prepared by photopolymerisation of N-isopropylacrylamide and 1-vinyl-2-pyrrolidinone in appropriate amounts of distilled water. The monomers were cured using a UV-light sensitive initiator called 1-hydroxycyclohexylphenylketone. These copolymers were crosslinked using ethylene glycol dimethacrylate and poly(ethylene glycol) dimethacrylate with molecular weights 600 and 1,000, at 0.1 wt% of the total monomer content. The chemical structure of the xerogels was characterised by means of Fourier transform infrared spectroscopy (FTIR) and the transition temperature of the hydrogels was determined using modulated differential scanning calorimetry (MDSC). By altering the feed ratio, hydrogels were synthesised to have lower critical solution temperatures (LCST) around 37 °C. This ability to shift the phase transition temperature of the gels provides excellent flexibility in tailoring transitions for specific uses. The samples synthesised with PEG1000DMA crosslinking agents absorbed over 18 times their weight in water, while maintaining good gel integrity thus falling marginally short of being characterised as superabsorbent. Each of the samples showed similar deswelling behaviour at 37 °C. Rheological studies showed that increasing the molecular weight of the crosslinking agent caused an increase in hydrogel strength.     

Preparation and mechanical characterization of a PNIPA hydrogel composite

A poly (N-isopropylacrylamide) (PNIPA) hydrogel was synthesized by free radical polymerization and reinforced with a polyurethane foam to make a hydrogel composite. The temperature dependence of the elastic modulus of the PNIPA hydrogel and the composite due to volume phase transition was found using a uniaxial compression test, and the swelling property was investigated using an equilibrium swelling ratio experiment. The gel composite preserves the ability to undergo the volume phase transition and its elastic modulus has strong temperature dependence. The temperature dependence of the elastic modulus and swelling ratio of the gel composite were compared to the PNIPA hydrogel. Not surprisingly, the modulus and swelling ratio of the composite were less dramatic than in the gel.     

Formulation and characterization of chitosan-based hydrogel films having both temperature and pH sensitivity

Chitosan-based hydrogel films having both temperature and pH sensitivity were prepared by blending chitosan with temperature sensitive poly (N-isopropylacrylamide) (PNIPAAm) and polyethylene glycol (PEG, Mw 2000). PEG was added to enhance film properties, such as thermal, mechanical and swelling properties. Differential scanning calorimetry (DSC) study indicated that the physically blended films exhibited a lower critical solution temperature (LCST) identical to that of pure PNIPAAm (around 32 °C). FT-IR data indicated that the temperature sensitivity is due to the PNIPAAm component in the film. The thermal analysis showed that chitosan and PNIPAAm were compatible and the blended films are apt to crystallize. The X-ray diffraction study further showed that the blended films had a higher crystallinity level than chitosan or PNIPAAm alone. The newly formed crystalline domains acted as physical crosslinkers and greatly increased the crosslinking level of the blended films, which, in turn, affected the swelling behavior and mechanical property of the blended films. Scanning electron microscopy (SEM) revealed that the blended swollen films exhibited a more porous structure at 37 °C (>LCST) than at room temperature (<LCST), though their swelling ratios were reduced as temperature increased from room temperature to 37 °C because of the dehydration nature of PNIPAAm at temperatures above its LCST. The results demonstrated that physically blended temperature sensitive films could be formulated, which are capable of producing more pores upon heating. The blended films were also found to be pH sensitive due to the fact that chitosan, one of the film components, has many pendant amino groups.     

Intelligent poly(<Emphasis Type="Italic">N</Emphasis>-isopropylacrylamide)-carboxymethyl cellulose full interpenetrating polymeric networks for protein adsorption studies

Poly(N-isopropyl acrylamide) (PNIPAm)–carboxymethyl cellulose (CMC) full interpenetrating polymeric networks (IPNs), based on PNIPAm and CMC, were prepared and investigated for adsorption of biomolecules utilizing a model protein, bovine serum albumin (BSA). N-isopropyl acrylamide monomers were polymerized in the presence of a natural polymer, e.g., carboxymethyl cellulose sodium salt. N,N′-methylenebisacrylamide (CL) was used to crosslink PNIPAm and CMC chains and IPN formed simultaneously. Spectroscopic and thermal characterization of the hydrogels were done with IR spectroscopy and thermogravimetric analysis. The swelling properties of PNIPAm and PNIPAm–CMC hydrogels were investigated as functions of the medium pH, temperature, ionic strength, and BSA. It was observed that the adsorption of protein molecules onto the hydrogels was mainly dependent on temperature and pH of the environment during the experiments. The maximum adsorption capacity (X) was observed at pH 4.7 which is the isoelectric point of BSA and at 40 °C for both hydrogels; and introducing CMC to PNIPAm increased the protein adsorption of the hydrogel. Adsorbed amounts of BSA were 26.70 mg g⁻¹ (4 °C) and 38.70 mg g⁻¹ (40 °C) for PNIPAm–CMC full IPN hydrogels. Adsorbed BSA (up to 80%) was eluted in the elution medium containing 0.1 mol dm⁻³ NaSCN at pH 8.0. Synthesized cylindrically shaped PNIPAm–CMC full IPN hydrogels can be used for adsorption studies related to the removal of proteins in pH- and temperature-sensitive biotechnological areas.     

Synthesis and characterization of a thermo-sensitive poly(N-methyl acryloylglycine methyl ester) used as a drug release carrier

In this article, poly(N-methyl acryloylglycine methyl ester) (PNMAME) was prepared as a novel thermosensitive material with a lower critical solution temperature (LCST) at around 49.5°C. The chemical structures of the monomer NMAME and PNMAME were characterized by ¹H NMR and IR measurements. The LCST was investigated systematically as a function of PNMAME concentration, inorganic salt solution and pH value. The results indicated that LCST of PNMAME was obviously dependent on PNMAME concentration and pH. The LCST was increased with a decrease in pH value and PNMAME concentration. To obtain a thermo-sensitive hydrogel with the phase transition temperature close to human body temperature, the copolymerization was conducted between NMAME and N-acryloylglycine ethyl ester (NAGEE). The release behavior of caffeine was evaluated at different temperatures and contents of cross-linkers (N, N-methylenebis(acrylamide) (NMBA)). The increase of cross-linker content led to a decrease in the release rate of caffeine due to higher crossing density in the hydrogel network. In addition, a faster release of caffeine from the hydrogel with 3% NMBA at 37°C was found in contrast to that at 18°C.     

Synthesis and characterization of a thermo-sensitive poly(<Emphasis Type="Italic">N</Emphasis>-methyl acryloylglycine methyl ester) used as a drug release carrier

In this article, poly(N-methyl acryloylglycine methyl ester) (PNMAME) was prepared as a novel thermosensitive material with a lower critical solution temperature (LCST) at around 49.5°C. The chemical structures of the monomer NMAME and PNMAME were characterized by ¹H NMR and IR measurements. The LCST was investigated systematically as a function of PNMAME concentration, inorganic salt solution and pH value. The results indicated that LCST of PNMAME was obviously dependent on PNMAME concentration and pH. The LCST was increased with a decrease in pH value and PNMAME concentration. To obtain a thermo-sensitive hydrogel with the phase transition temperature close to human body temperature, the copolymerization was conducted between NMAME and N-acryloylglycine ethyl ester (NAGEE). The release behavior of caffeine was evaluated at different temperatures and contents of cross-linkers (N, N-methylenebis(acrylamide) (NMBA)). The increase of cross-linker content led to a decrease in the release rate of caffeine due to higher crossing density in the hydrogel network. In addition, a faster release of caffeine from the hydrogel with 3% NMBA at 37°C was found in contrast to that at 18°C.     

Cell attachment/detachment behavior on poly(<Emphasis Type="Italic">N</Emphasis>-isopropylacrylamide)-based microgel films: the effect of microgel structure and swelling ratio

Microgels are cross-linked soft particles with a three-dimensional network structure that are swollen in a good solvent. Poly(N-isopropylacrylamide) (pNIPAAm)-based microgels have attracted great attentions for their temperature responsive property, particularly in recent years, pNIPAAm-based microgel films were utilized as a new kind of thermoresponsive surface to tune cell attachment/detachment behavior via temperature stimuli. However, some results are not consistent, for example, different polymerization conditions may bring out different results even for pure pNIPAAm microgel. This work aims to find out which factor plays the critical role for successful cell detachment on the pNIPAAm-based microgel films. The results unraveled that the structure and swelling ratio of the microgel rather than the film thickness plays a key role on the successful cells detachment, unlike linear pNIPAAm films in which the cells’ attach/detach property is only determined by the film thickness. For poly(N-isopropylacrylamide–styrene) microgel film, NIH3T3 cells could only detach when the microgel has a uniform structure and the volume dilatation of the microgel (20/38 °C) is larger than 4.     

Templated synthesis of mesoporous aluminas by <Emphasis Type="Italic">graft</Emphasis> copolymer and their CO<Subscript>2</Subscript> adsorption capacities

Mesoporous aluminas were synthesized via a sol–gel process by templating an amphiphilic graft copolymer, PVC–g–POEM, consisting of a poly(vinyl chloride) (PVC) backbone and poly(oxyethylene methacrylate) (POEM) side chains. The mesoporous structures of aluminas with large surface areas were confirmed by X-ray diffraction, transmission electron microscopy, and nitrogen adsorption/desorption analysis. Aluminas synthesized with PVC–g–POEM graft copolymer exhibited higher CO₂ adsorption capacities (0.7 mol CO₂/kg sorbent) than aluminas synthesized without graft copolymer (0.6 mol CO₂/kg sorbent). The adsorption capacity of alumina strongly depends on its structure and calcination temperature; amorphous (400 °C) > γ phase (800 °C) > α phase (1000 °C).     

Preparation of hydrogel capsules with thermoresponsive interpenetrating polymer network using concentric two-fluid nozzles

Hydrogel capsules in which shell was composed of thermoresponsive interpenetrating polymer network (IPN) of crosslinked poly(N-isopropylacrylamide) (PNIAPM) and calcium alginate, were prepared using concentric two-fluid nozzles. To introduce different amount of PNIPAM into the capsule shell, the concentrations of the NIPAM monomer and the polymerization initiator were changed in a wide range and the characteristics of the resulting capsules were evaluated. Spherical and uniformly sized capsules were obtained under all conditions. Elemental analyses showed that the PNIPAM/alginate weight ratio increased with the increase of initial concentrations of NIPAM monomer and polymerization initiator and was proportional to the initial rate of polymerization. In addition, the thermoresponsive properties of IPN hydrogel capsule were measured at temperatures from 10 °C to 50 °C and the thermoresponsive volume change ratio was expressed as a function of the PNIPAM/alginate weight ratio raised to a power. From these results, the relationship between the experimental conditions and the amount of PNIPAM in the capsule shell was clarified, and it indicated the magnitude of volume change of IPN hydrogel capsules can be controlled by introducing the desired amount of PNIPAM in the capsules.     

Preparation,properties, and drug release of thermo- and pH-sensitive poly((2-dimethylamino)ethyl methacrylate)/poly(<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-diethylacrylamide) semi-IPN hydrogels

In this paper, a series of semi-interpenetrating polymer network (semi-IPN) hydrogels based on poly((2-dimethylamino)ethyl methacrylate)/poly (N,N-diethylacrylamide) (PDMAEMA/PDEA) were synthesized by changing the initial PDMAEMA/DEA molar ratio at room temperature. The influence of this additive on the property of resulting PDEA hydrogels was investigated and characterized. The interior morphology by scanning electron microscopy (SEM) revealed that the semi-IPN hydrogels have interconnected porous network structures. The glass transition temperature (T _g) of the semi-IPN hydrogels was observed by differential scanning calorimetry (DSC). Equilibrium swelling ratio (ESR), swelling and deswelling dynamics of the hydrogels responding to temperature and pH were investigated in detail. Compared to PDEA, the semi-IPN hydrogels exhibited excellent mutative values in response to an alternation of the temperature and pH, and showed fast swelling and deswelling rates in response to temperature and pH change. The release behaviors of the model drug, aminophylline, were found dependent on hydrogel compositions and environmental temperature. These results suggest that the stimuli semi-IPN hydrogel have potential application as intelligent drug carriers.     

Synthesis and characterization of a pH/temperature responsive glycine-mediated hydrogel for drug release

In this work, a pH/temperature responsive hydrogel (PMEA) from N-acryloylglycine methyl ester (NAGME), N-acryloylglycine ethyl ester (NAGEE), and acrylic acid (AAc) was synthesized by free radical polymerization. The swelling behaviors and drug release properties of hydrogels were systematically investigated at different temperature, pH, and AAc content. It was found that the hydrogel PMEA demonstrated pH and temperature responsive nature. The caffeine-release behaviors showed that only 49.1% caffeine was released from PMEA in pH 2.70 phosphate buffer solution (PBS) after 500 minutes, whereas more than 93.9% caffeine was gradually diffused into the medium in pH 7.49 PBS over the same time interval. In addition, the caffeine release was much higher at 37°C than that at 14°C in deionized water. As seen from the results, the PMEA seems to be a potential drug carrier with pH-temperature responsiveness.     

Stimuli-responsive chitosan/poly (<Emphasis Type="Italic">N</Emphasis>-isopropylacrylamide) semi-interpenetrating polymer networks: effect of pH and temperature on their rheological and swelling properties

The aim of this work was to synthesize semi-interpenetrating polymer networks (semi-IPNs) by free radical polymerization of N-isopropylacrylamide [poly (NIPAAm)], in the presence of chitosan (CHI), and to study the effect of pH and temperature changes on their rheological and swelling properties. The semi-IPNs are thermally stable up to about 400 °C and the presence of CHI increases the thermal degradation rate compared to bare poly (NIPAAm). The prepared systems presents a well-defined porosity and proved to be non-toxic, in vitro, on human embryonic skin fibroblast, thus offering appropriate support for cell proliferation. The semi-IPNs present, at physiological pH, swelling degrees well below those of the pure poly (NIPAAm). Differently, at acidic pH, the CHI macromolecules are protonated and become much more permeable to the diffusion of water giving a swelling degree that approaches that of bare poly (NIPAAm). The viscoelastic moduli of the semi-IPNs increase as a function of pH while the LCST remain unchanged. Moreover, the semi-IPNs viscoelastic moduli increase with the increase of CHI content and, in particular, the difference between the elastic modulus before and after the sol/gel transition is higher for the semi-IPN than for bare poly (NIPAAm) just at about physiological conditions.     

Microstructural effects on the phase transitions and the thermal evolution of elastic and piezoelectric properties in highly dense,submicron-structured NaNbO<Subscript>3</Subscript> ceramics

The dielectric, piezoelectric and elastic coefficients, as well as the electromechanical coupling factors, of NaNbO₃ submicron-structured ceramics have been obtained by an automatic iterative method from impedance measurements at resonance. Poled thin discs were measured from room temperature up to the depoling one, close to 300 °C. Dielectric thermal behaviour was determined also for unpoled ceramics up to the highest phase transition temperature. Ceramics were processed by hot-pressing from mechanically activated precursors. Microstructural effects on the properties are discussed. The suppression of the classical maximum in dielectric permittivity in unpoled ceramics at the phase transition at 370 °C was found when a bimodal distribution of grain sizes, with a population of average grain size of 110 nm in between much coarser grains, is observed. The appearance of a phase transition at 150 °C took place when Na vacancies are minimised. The occurrence of a non-centrosymmetric, ferroelectric phase, in the unpoled ceramic from room temperature to ~300 °C, highly polarisable resulting in high ferro–piezoelectric properties was also observed in the ceramic which presents grain size below 160 nm. Maximum values of k _p = 14%, d ₃₁ = −8.7 × 10⁻¹² C N⁻¹ and N _p = 3772 Hz m at room temperature, and k _p = 18%, d ₃₁ = −25.4 × 10⁻¹² C N⁻¹ and N _p = 3722 Hz m at 295 °C were achieved in the best processing conditions of the ceramics.     

Magnet–PNIPA hydrogels for bioengineering applications

Temperature-sensitive Poly (N-isopropylacrylamide), PNIPA gels were synthesized with micron-sized iron and iron oxide (Fe₃O₄) particles to investigate their viability for hyperthermia applications. Induction heating of the magnetic hydrogels with varying concentration of magnetic powder was conducted at a frequency of 375  kHz for magnetic field strength varying from 1.7 kA/m (21 Oe) to 2.5 kA/m (31.4 Oe). It was observed that the maximum temperature induced in the magnetic hydrogels increased with the concentration of magnetic particles and magnetic field strength. The PNIPA gel underwent a collapse transition at 34 °C. It was found that a 2.5 wt.% Fe₃O₄ in PNIPA composite took 260 s to be heated to 45 °C under a magnetic field strength of 1.7 kA/m, the specific absorption rate (SAR) was found to be 1.83. SAR of iron oxide was found to be higher than the SAR of iron.     

Injectable thermosensitive hydrogel based on chitosan and quaternized chitosan and the biomedical properties

A novel injectable thermosensitive hydrogel (CS–HTCC/α β-GP) was successfully designed and prepared using chitosan (CS), quaternized chitosan (HTCC) and α,β-glycerophosphate (α,β-GP) without any additional chemical stimulus. The gelation point of CS–HTCC/α β-GP can be set at a temperature close to normal body temperature or other temperature above 25°C. The transition process can be controlled by adjusting the weight ratio of CS to HTCC, or different final concentration of α,β-GP. The optimum formulation is (CS + HTCC) (2% w/v), CS/HTCC (5/1 w/w) and α,β-GP 8.33% or 9.09% (w/v), where the sol–gel transition time was 3 min at 37°C. The drug released over 3 h from the CS–HTCC/α,β-GP thermosensitive hydrogel in artificial saliva pH 6.8. In addition, CS–HTCC/α,β-GP thermosensitive hydrogel exhibited stronger antibacterial activity towards two periodontal pathogens (Porphyromonas gingivalis, P.g and Prevotella intermedia, P.i). CS–HTCC/α, β-GP thermosensitive hydrogel was a considerable candidate as a local drug delivery system for periodontal treatment.     

Cationic poly(VCL–AETA) hydrogels and ovalbumin (OVA) release in vitro

The objective of this research is to explore the synthesis of a new family of water soluble polycationic copolymeric precursors that could be photo-crosslinked into hydrogels. The in vitro control release of ovalbumin protein (OVA) from this family of hydrogels was also studied to assess the biomedical potential of this new family polycationic hydrogels. A series of novel poly(VCL–AETA) copolymer hydrogels was fabricated in an aqueous medium via photo-induced polymerization and crosslinking of hydrophobic N-vinylcaprolactam (VCL) and hydrophilic [2-(acryloxy)ethyl]trimethylammonium chloride (AETA) monomers over a wide range of VCL to AETA feed molar ratios of 2:1, 1:1, 1:2, 1:5. N,N′-methylene bisacrylamide (MBA) was used as a crosslinker. Ovalbumin (OVA), a model antigen, was preloaded into poly(VCL–AETA) hydrogel precursors and its release profiles in pH 7.4 PBS at 37°C were investigated as a function of VCL to AETA monomer feed ratios over a period of 4 weeks. The in vitro results showed that OVA initial burst and subsequent sustained releases could be controlled by 3 material parameters: the hydrophobic VCL to hydrophilic AETA monomer feed ratios, crosslinking density and hydrogel degradation rate. Thus, the hydrophobic-hydrophilic VCL–AETA hydrogel network for controlled OVA release could offer advantages over organic solvent-based single component polymer system. However, these in vitro OVA release profiles may change in an in vivo environment.     

Thermoresponsive hyperbranched copolymer with multi acrylate functionality for in situ cross-linkable hyaluronic acid composite semi-IPN hydrogel

Thermoresponsive polymers have been widely used for in situ formed hydrogels in drug delivery and tissue engineering as they are easy to handle and their shape can easily conform to tissue defects. However, non-covalent bonding and mechanical weakness of these hydrogels limit their applications. In this study, a physically and chemically in situ cross-linkable hydrogel system was developed from a novel thermoresponsive hyperbranched PEG based copolymer with multi acrylate functionality, which was synthesized via an ‘one pot and one step’ in situ deactivation enhanced atom transfer radical co-polymerization of poly(ethylene glycol) diacrylate (PEGDA, M_n = 258 g mol⁻¹), poly(ethylene glycol) methyl ether methacrylate (PEGMEMA, M_n = 475 g mol⁻¹) and (2-methoxyethoxy) ethyl methacrylate (MEO₂MA). This hyperbranched copolymer was tailored to have the lower critical solution temperature to form physical gelation around 37°C. Meanwhile, with high level of acrylate functionalities, a chemically cross-linked gel was formed from this copolymer using thiol functional cross-linker of pentaerythritol tetrakis (3-mercaptopropionate) (QT) via thiol-ene Michael addition reaction. Furthermore, a semi-interpenetrated polymer networks (semi-IPN) structure was developed by combining this polymer with hyaluronic acid (HA), leading to an in situ cross-linkable hydrogel with significantly increased porosity, enhanced swelling behavior and improved cell adhesion and viability both in 2D and 3D cell culture models.