Multiphoton Lithography of Interpenetrating Polymer Networks for Tailored Microstructure Thermal and Micromechanical Properties.

Multiphoton lithography (MPL), an emerging truly 3D microfabrication technique, exhibits substantial potential in biomedical applications, including drug delivery and tissue engineering. Fabricated micro-objects are often expected to undergo shape morphing or bending of the entire structure or its parts. Furthermore, ensuring precise property tuning is detrimental to the realization of the functionality of MPL microstructures. Herein, novel MPL materials based on interpenetrating polymer networks (IPNs) are presented that effectively combine the advantages of acrylate and epoxy systems. IPNs with varying component ratios are investigated for their microfabrication performance and structural integrity with respect to thermal and micromechanical properties. A variety of high-resolution techniques is applied to comprehensively evaluate IPN properties at the bulk, micron, and segmental levels. This study shows that the MPL laser scanning velocity and power, photoinitiator content, and multi-step exposure can be used to tune the morphology and properties of the IPN. As a result, a library of 3D MPL IPN microstructures with high 3D structural stability and tailored thermal and micromechanical properties is achieved. New IPN microstructures with Young's moduli of 3-4 MPa demonstrate high-to-fully elastic responses to deformations, making them promising for applications in morphable microsystems, soft micro-robotics, and cell engineering.

Achieving 1060 mW cm-2 with 0.6 mg cm-2 Pt Loading Based on Imidazole-Riched Semi-Interpenetrating Proton Exchange Membrane at High-Temperature Fuel Cells.

Enhancing phosphoric acid (PA) doping in polybenzimidazole (PBI) membranes is crucial for improving the performance of high-temperature proton exchange membrane fuel cells (HT-PEMFCs). However, excessive PA uptake often leads to drawbacks such as PA loss and compromised mechanical properties when surpassing PA capacity of PBI basic functionality. Herein, a new strategy that integrates high PA uptake, mechanical strength, and acid retention is proposed by embedding linear PBI chains into a crosslinked poly(N-vinylimidazole) (PVIm) backbone via in-situ polymerization. The imidazole (Im)-riched semi-interpenetrating polymer network (sIPN) membrane with high-density nitrogen moieties, significantly enhancing the PA doping degree to 380% shows an excellent conductivity (0.108 S cm-1). Meanwhile, the crosslinking structure in the sIPN membrane ensures adequate mechanical properties, low hydrogen permeability, and a relatively low swelling ratio. As a result, the single cell based on the membrane achieves the highest power density of 1060 mW cm-2 with a low Pt loading (0.6 mg cm-2) up to now and exhibits excellent fuel cell stability.

Semi-Interpenetrating Polymer Network Anion Exchange Membranes Based on Quaternized Polybenzoxazine and Poly(Vinyl Alcohol-Co-Ethylene) for Acid Recovery by Diffusion Dialysis.

Acid recovery from acidic waste is a pressing issue in current times. Chemical methods for recovery are not economically feasible and require significant energy input to save the environment. This study reported a semi-interpenetrating polymer network (semi-IPN) anion exchange membranes (AEMs) for acid recovery by diffusion dialysis with excellent dimensional stability, high oxidation stability, good acid dialysis coefficient (UH +) and high separation factor (S). Semi-IPN AEMs are prepared by ring-open cross-linked quaternized polybenzoxazine (AQBZ) with poly(vinyl alcohol-co-ethylene), where AQBZ is obtained by Mannich reaction and Menshutkin reaction. All four proportions of semi-IPNs exhibit clear micro-phase separation, which is conducive to ion transport. The water uptake (WU) of the four semi-IPNs ranges from 14.2 % to 19.2 %, while the swelling ratio (SR) remains between 8.7 % and 11.3 %. These results indicate that the cross-linked structure in the designed semi-IPNs effectively control swelling and ensure dimensional stability. The thermal degradation temperature (Td5) of semi-IPN4:6 to semi-IPN7:3 varies from 309 °C to 289 °C, with an oxidation stability weight loss rate (WOX) ranging from 91.5 % to 93.5 %, demonstrating excellent thermal stability and oxidation stability. The semi-IPNs also show good UH + values ranging from 11.9-16.3*10-3 m/h and high S values between 38.6 and 45.9, indicating the promising potential of the semi-IPNs.

Functional Semi-Interpenetrating Polymer Networks.

Semi-interpenetrating polymer networks (SIPNs) have garnered significant interest due to their potential applications in self-healing materials, drug delivery systems, electrolytes, functional membranes, smart gels and, toughing. SIPNs combine the characteristics of physical cross-linking with advantageous chemical properties, offering broad application prospects in materials science and engineering. This perspective introduces the history of semi-interpenetrating polymer networks and their diverse applications. Additionally, the ongoing challenges associated with traditional semi-interpenetrating polymer materials are discussed and provide an outlook on future advancements in novel functional SIPNs.

Development of Gelatin Methacryloyl/Sodium Alginate Interpenetrating Polymer Network Hydrogels for Bone Regeneration by Activating the Wnt/ß-Catenin Signaling Pathway via Lithium Release.

Hydrogels have gained significant attention as biomaterials due to their remarkable properties resembling those of the extracellular matrix (ECM). In the present investigation, we successfully synthesized interpenetrating polymer network (IPN) hydrogels using gelatin methacryloyl (GelMA) and sodium alginate (SA), incorporating various concentrations of lithium chloride (LiCl; 0, 5, and 10 mM), aiming to develop a hydrogel scaffold for bone regeneration. Notably, the compressive modulus of the IPN hydrogels remained largely unaffected upon the inclusion of LiCl. However, the hydrogel with the high concentration of LiCl exhibited reduced fragmentation after compression testing. Intriguingly, we observed a significant improvement in cellular biocompatibility, primarily attributed to activation of the Wnt/ß-catenin signaling pathway induced by LiCl. Subsequently, we evaluated the efficacy of the newly developed IPN-Li hydrogels in a rat cranial defect model and found that they substantially enhanced bone regeneration. Nevertheless, it is important to note that the introduction of high concentrations of LiCl did not significantly promote osteogenesis. This outcome can be attributed to the excessive release of Li+ ions into the extracellular matrix, hindering the desired effect. Overall, the IPN-Li hydrogel developed in this study holds great promise as a biodegradable material for bone regeneration applications.

Characterization of structural and functional properties of soy protein isolate and sodium alginate interpenetrating polymer network hydrogels.

BACKGROUND: This study used enzymatic and Ca2+ cross-linking methods to prepare edible soy protein isolate (SPI) and sodium alginate (SA) interpenetrating polymer network hydrogels to overcome the disadvantages of traditional interpenetrating polymer network (IPN) hydrogels, such as poor performance, high toxicity, and inedibility. The influence of changes in SPI and SA mass ratio on the performance of SPI-SA IPN hydrogels was investigated. RESULTS: Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to characterize the structure of the hydrogels. Texture profile analysis (TPA), rheological properties, swelling rate, and Cell Counting Kit-8 (CCK-8) were used to evaluate physical and chemical properties and safety. The results showed that, compared with SPI hydrogel, IPN hydrogels had better gel properties and structural stability. As the mass ratio of SPI-SA IPN changed from 1:0.2 to 1:1, the gel network structure of hydrogels also tended to be dense and uniform. The water retention and mechanical properties of these hydrogels, such as storage modulus (G'), loss modulus (G"), and gel hardness increased significantly and were greater than those of the SPI hydrogel. Cytotoxicity tests were also performed. The biocompatibility of these hydrogels was good. CONCLUSIONS: This study proposes a new method to prepare food-grade IPN hydrogels with mechanical properties of SPI and SA, which may have strong potential for the development of new foods. © 2023 Society of Chemical Industry.

Removal of cationic dye pollutants from wastewater with HS loaded semi-IPN composites: kinetic and thermodynamic studies.

In this study, methylene blue (MB) pollutant in water was removed using produced hazelnut shell loaded semi-interpenetrating polymer networks (HS loaded semi-IPN) adsorbent. The physical and chemical characterizations of the adsorbents were investigated using TGA, DSC, FT-IR, BET, FE-SEM, and EDX. Experimental parameters such as temperature, swelling, dye concentration, contact time, pH solution, and adsorbent dosage for MB adsorption were thoroughly investigated. It was determined that the HS loaded semi-IPN adsorbent removed 92.1% of MB dye. Subsequently, the adsorption properties between the adsorbent and dye were investigated in detail using several different kinetic, isotherm, and thermodynamic models. As a result of the obtained data, the interaction between adsorbent and dye molecules is discussed. Moreover, studies on the industrial usability of the adsorbent have been carried out, and it has been observed that the adsorbent can be employed even after four cycles.

Design, development and characterization of interpenetrating polymer network hydrogel bead for controlled release of glipizide drug.

In the current study, a novel interpenetrating polymer network (IPN) hydrogel bead was developed by encapsulation of antidiabetic drug glipizide using sodium alginate (SAL) and xanthan gum (XAG) biopolymers by ionotropic gelation technique with calcium chloride as cross-linking agent. In light of the fact that IPN hydrogel beads possess greater benefits in controlling the release of such short acting drug, sodium alginate and xanthan gum IPN hydrogel beads were prepared at different mass ratios (SAL:XAG = 10:0, 9:1, 8:2, 7:3, 6:4, 5:5). Similarly, drug-loaded IPN hydrogel beads were also developed. The prepared hydrogel beads were investigated using Fourier transform infrared spectroscopy, X-ray powder diffraction, and thermogravimetric studies to understand the type of interactions between the composite beads. Surface morphology changes were studied by scanning electron microscopy. The particle size, drug entrapment efficiency, and swelling behavior of prepared hydrogel beads were also studied. Based on in vitro drug dissolution studies, it was observed that SXF4 preparation containing SAL and XAG polymers at 7:3 ratio showed extended drug release of 97.53% at 9 h. This study demonstrated that inclusion of XAG has extended the drug release and able to achieve zero-order drug release profile.

Superabsorbent Hydrogels Based to Polyacrylamide/Cashew Tree Gum for the Controlled Release of Water and Plant Nutrients.

Agricultural production is influenced by the water content in the soil and availability of fertilizers. Thus, superabsorbent hydrogels, based on polyacrylamide, natural cashew tree gum (CG) and potassium hydrogen phosphate (PHP), as fertilizer and water releaser were developed. The structure, morphology, thermal stability and chemical composition of samples of polyacrylamide and cashew tree gum hydrogels with the presence of fertilizer (HCGP) and without fertilizer (HCG) were investigated, using X-ray diffractometry (XRD), Fourier Transformed Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TGA/DTG) and Energy Dispersive Spectroscopy (EDS). Swelling/reswelling tests, textural analysis, effect of pH, release of nutrients and kinetics were determined; the ecotoxicity of the hydrogels was investigated by the Artemia salina test. The results showed that PHP incorporation in the hydrogel favored the crosslinking of chains. This increased the thermal stability in HCGP but decreased the hardness and adhesion properties. The HCGP demonstrated good swelling capacity (~15,000 times) and an excellent potential for reuse after fifty-five consecutive cycles. The swelling was favored in an alkaline pH due to the ionization of hydrophilic groups. The sustained release of phosphorus in HCGP was described by the Korsmeyer-Peppas model, and Fickian diffusion is the main fertilizer release mechanism. Finally, the hydrogels do not demonstrate toxicity, and HCGP has potential for application in agriculture.

NIR-Sensitized Cationic and Hybrid Radical/Cationic Polymerization and Crosslinking.

NIR-sensitized cationic polymerization proceeded with good efficiency, as was demonstrated with epoxides, vinyl ether, and oxetane. A heptacyanine functioned as sensitizer while iodonium salt served as coinitiator. The anion adopts a special function in a series selected from fluorinated phosphates (a: [PF6 ]- , b: [PF3 (C2 F5 )3 ]- , c: [PF3 (n-C4 F9 )3 ]- ), aluminates (d: [Al(O-t-C4 F9 )4 ]- , e: [Al(O(C3 F6 )CH3 )4 ]- ), and methide [C(O-SO2 CF3 )3 ]- (f). Vinyl ether showed the best cationic polymerization efficiency followed by oxetanes and oxiranes. DFT calculations provided a rough pattern regarding the electrostatic potential of each anion where d showed a better reactivity than e and b. Formation of interpenetrating polymer networks (IPNs) using trimethylpropane triacrylate and epoxides proceeded in the case of NIR-sensitized polymerization where anion d served as counter ion in the initiator system. No IPN was formed by UV-LED initiation using the same monomers but thioxanthone/iodonium salt as photoinitiator. Exposure was carried out with new NIR-LED devices emitting at either 805 or 870 nm.

An Interpenetrating Alginate/Gelatin Network for Three-Dimensional (3D) Cell Cultures and Organ Bioprinting.

Crosslinking is an effective way to improve the physiochemical and biochemical properties of hydrogels. In this study, we describe an interpenetrating polymer network (IPN) of alginate/gelatin hydrogels (i.e., A-G-IPN) in which cells can be encapsulated for in vitro three-dimensional (3D) cultures and organ bioprinting. A double crosslinking model, i.e., using Ca2+ to crosslink alginate molecules and transglutaminase (TG) to crosslink gelatin molecules, is exploited to improve the physiochemical, such as water holding capacity, hardness and structural integrity, and biochemical properties, such as cytocompatibility, of the alginate/gelatin hydrogels. For the sake of convenience, the individual ionic (i.e., only treatment with Ca2+) or enzymatic (i.e., only treatment with TG) crosslinked alginate/gelatin hydrogels are referred as alginate-semi-IPN (i.e., A-semi-IPN) or gelatin-semi-IPN (i.e., G-semi-IPN), respectively. Tunable physiochemical and biochemical properties of the hydrogels have been obtained by changing the crosslinking sequences and polymer concentrations. Cytocompatibilities of the obtained hydrogels are evaluated through in vitro 3D cell cultures and bioprinting. The double crosslinked A-G-IPN hydrogel is a promising candidate for a wide range of biomedical applications, including bioartificial organ manufacturing, high-throughput drug screening, and pathological mechanism analyses.

High-Speed 3D Printing of High-Performance Thermosetting Polymers via Two-Stage Curing.

Design and direct fabrication of high-performance thermosets and composites via 3D printing are highly desirable in engineering applications. Most 3D printed thermosetting polymers to date suffer from poor mechanical properties and low printing speed. Here, a novel ink for high-speed 3D printing of high-performance epoxy thermosets via a two-stage curing approach is presented. The ink containing photocurable resin and thermally curable epoxy resin is used for the digital light processing (DLP) 3D printing. After printing, the part is thermally cured at elevated temperature to yield an interpenetrating polymer network epoxy composite, whose mechanical properties are comparable to engineering epoxy. The printing speed is accelerated by the continuous liquid interface production assisted DLP 3D printing method, achieving a printing speed as high as 216 mm h-1 . It is also demonstrated that 3D printing structural electronics can be achieved by combining the 3D printed epoxy composites with infilled silver ink in the hollow channels. The new 3D printing method via two-stage curing combines the attributes of outstanding printing speed, high resolution, low volume shrinkage, and excellent mechanical properties, and provides a new avenue to fabricate 3D thermosetting composites with excellent mechanical properties and high efficiency toward high-performance and functional applications.

Creep Behavior of Resin Composite Interface Between Orthodontic Brackets and Enamel.

PURPOSE: The present study investigated the creep of adhesive resin under constant loading at the orthodontic bracket/enamel interface with an orthodontic bracket-tooth model (shear creep) and three-point bending test (bending creep). MATERIALS AND METHODS: For the bracket-tooth model, sixty premolars were assigned to 4 groups (n = 15). Orthodontic brackets were bonded onto the enamel surface using four different bonding agents: conventional, homogeneous Transbond XT orthodontic composite (group 1/TBC); Transbond XT composite reinforced with photopolymerized glass-fiber-reinforced composite (FRC with bidirectional fibers) (group 2/TBE); Transbond XT reinforced with FRC of vertically oriented unidirectional fibers (group 3/TBV); and Transbond XT reinforced with FRC of horizontally oriented fibers (group 4/TBH). Load was applied at the bracket/tooth interface and from the bracket wire slot. In the three-point bending test, the creep and recovery of the rectangular interface materials were tested by a dynamic mechanical analyzer. The data obtained were statistically analyzed with ANOVA and a post-hoc test using SPSS v20 statistical software. RESULTS: The groups exhibited significant differences in strain % and time for bracket deflection at the interface (p < 0.05). The interface loading with unidirectional fibers (groups TBV and TBH) were statistically significantly different compared to the interface with bidirectional fibers and control group (groups TBE and TBC). The three-point test showed the least creep compliance (ie, creep deformation occurring at each time point [J]) with group TBC, followed by groups TBV and TBE. Group TBC showed the highest nanohardness and elastic modulus; the lowest values were seen in group TBE, reflecting differences in polymer matrix composition. CONCLUSION: The creep and time for debonding the bracket increased with incorporation of glass fibers at the interface between bracket and enamel.

Synthesis and characterisation of cross-linked chitosan composites functionalised with silver and gold nanoparticles for antimicrobial applications.

We present a study of a range of cross-linked chitosan composites with potential antimicrobial applications. They were formed by cross-linking chitosan and siloxane networks and by introducing silver and gold nanoparticles (NPs). The aim was to investigate whether adding the metal NPs to the chitosan-siloxane composite would lead to a material with enhanced antimicrobial ability as compared to chitosan itself. The composites were synthesised in hydrogel form with the metal NPs embedded in the cross-linked chitosan network. Spectroscopic and microscopic techniques were employed to investigate the structural properties of the composite and the tensile strength of the structures was measured. It was found that the addition of metal NPs did not influence the mechanical strength of the composite. A crystal violet attachment assay results displayed a significant reduction in the attachment of E. coli to the cross-linked chitosan surfaces. Release profile tests suggest that the metal NPs do not contribute to the overall antimicrobial activity under neutral conditions. The contribution to the mechanical and antimicrobial properties from cross-linking with siloxane is significant, giving rise to a versatile, durable, antimicrobial material suitable for thin film formation, wound dressings or the coating of various surfaces where robustness and antimicrobial control are required.

Taste masking of azithromycin by resin complex and sustained release through interpenetrating polymer network with functionalized biopolymers.

OBJECTIVE: The objective was to evaluate taste masking of azithromycin (AZI) by ion exchange resins (IERs) and the formation of covalent semi interpenetrating polymer network (IPN) beads using chitosan (CS) and sodium carboxylated agarose (SCAG) for sustained release of drug. METHODS: Methacrylic acid (MAA)-based IERs were prepared by suspension polymerization method. Drug release complexes (DRCs) were prepared by different drug:resin ratios i.e. 1:1, 1:2 and 1:4. The resultant DRCs were characterized using DSC, FTIR, PXRD, in vivo and in vitro taste masking, and in vitro drug release at gastric pH. IPN beads were prepared by entrapping DRCs with bio polymers and cross linked with trisodium citrate (NaCIT), and further cross-linked with glutaraldehyde (GA) for sustained release of AZI. RESULTS: In vitro and in vivo taste masking studies showed that MD1:4 DRC formulation was optimal. The release of AZI from DRC was found to be very fast at gastric pH i.e. 97.37 ± 1.02% within 45 min. The formation of IPN beads was confirmed by FTIR. The release of drug from IPN beads at gastric and intestinal pH was found to be "<28% and <60%", respectively. The release kinetics showed Fickian diffusion profile for ionically cross-linked beads and zero-order release mechanism for GA cross-linking beads. CONCLUSIONS: DRCs can be effectively used for taste masking and newly formulated IPN beads demonstrated sustained release of AZI.

Controlling bacterial fouling with polyurethane/N-halamine semi-interpenetrating polymer networks.

N -halamine-based interpenetrating polymer networks were developed as a simple and effective strategy in the preparation of antimicrobial polymers. An N-halamine monomer, N-chloro-2, 2, 6, 6-tetramethyl-4-piperidyl methacrylate, was incorporated into polyurethane in the presence of a cross-linker and an initiator. Post-polymerization of the monomers led to the formation of polyurethane/N-halamine semi-interpenetrating polymer networks. The presence of N-halamines in the semi-interpenetrating polymer networks was confirmed by attenuated total reflectance infrared, water contact angle, and energy-dispersive X-ray spectroscopy analysis. The N-halamine contents in the semi-interpenetrating polymer networks could be readily controlled by changing reaction conditions. The distribution of active chlorines within the semi-interpenetrating polymer networks was characterized with energy-dispersive X-ray spectroscopy. Contact mode antimicrobial tests, zone of inhibition studies, and scanning electron microscopy observations showed that the semi-interpenetrating polymer networks had potent antimicrobial and antifouling effects against both Gram-positive and Gram-negative bacteria. Release tests demonstrated the outstanding stability of the N-halamine structures in the new semi-interpenetrating polymer networks.

In vivo and in vitro taste masking of ofloxacin and sustained release by forming interpenetrating polymer network beads.

Drug-resin complexes (DRCs) of ofloxacin and ion-exchange resins (IERs) were prepared in different ratios of drug/IERs, that is, 1:1, 1:2 and 1:4 (w/w) and investigated for taste masking by in vivo and in vitro release studies. Human volunteers graded AD1:4 (DRC) as tasteless with an average value of 0.3 ± 0.03 and in vitro study showed that AD 1:4 released only 1.70 ± 0.86% of drug at salivary pH within 30s. Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (P-XRD) and differential scanning calorimetry (DSC) studies of AD 1:4 showed the change in the morphology of the drug, that is, from crystalline phase to amorphous phase during complex formation. The release of drug from AD 1:4 was completed within 30 min at gastric pH 1.2 and to extend the release time of drug at gastric pH, it was entrapped with different biopolymers, such as sodium alginate (SA) and sodium carboxymethyl cellulose (SCMC), in the presence of ferric chloride and glutaraldehyde (GA) to form interpenetrating polymer network (IPN) beads. FTIR studies revealed that IPN beads were crosslinked with Fe3+ and GA. The release of drug at gastric and intestinal pH was 14.53 ± 1.52% and 65.86 ± 1.29%, respectively, for a contact time of 10 h. The kinetics release study shows fickian diffusion for ionically crosslinked beads and zero-order release for GA crosslinking beads.

In Vivo Evaluation of a PEO-Gellan Gum Semi-Interpenetrating Polymer Network for the Oral Delivery of Sulpiride.

In this study, an optimized epichlorohydrin-crosslinked semi-interpenetrating polymer network xerogel matrix system (XePoMas) for the controlled delivery of sulpiride was prepared. The ability of XePoMas to sustain drug release was determined by in vitro and in vivo drug release experiments. Swelling of the xerogel over the 24-h experimental period ranged from 346 to 648%; swelling was observed to increase exponentially over the initial 8 h. In vitro drug release depicted a linear zero order drug release profile with an R 2 value of 0.9956. The ability of the fabricated XePoMas to sustain drug release and enhance bioavailability of sulpiride in vivo was investigated by evaluating the plasma drug concentration over 24 h in the large pig model. The optimized XePoMas formulation was shown to increase intestinal absorption of sulpiride to a greater extent than the marketed product in vivo, with a C max of 830.58 ng/mL after 15 h.

Highly deformable and strongly magnetic semi-interpenetrating hydrogels based on alginate or cellulose.

The effective implementation of many of the applications of magnetic hydrogels requires the development of innovative systems capable of withstanding a substantial load of magnetic particles to ensure exceptional responsiveness, without compromising their reliability and stability. To address this challenge, double-network hydrogels have emerged as a promising foundation, thanks to their extraordinary mechanical deformability and toughness. Here, we report a semi-interpenetrating polymer networks (SIPNs) approach to create diverse magnetic SIPNs hydrogels based on alginate or cellulose, exhibiting remarkable deformability under certain stresses. Achieving strong responsiveness to magnetic fields is a key objective, and this characteristic is realized by the incorporation of highly magnetic iron microparticles at moderately large concentrations into the polymer network. Remarkably, the SIPNs hydrogels developed in this research accommodate high loadings of magnetic particles without significantly compromising their physical properties. This feature is essential for their use in applications that demand robust responsiveness to applied magnetic fields and overall stability, such as a hydrogel luminescent oxygen sensor controlled by magnetic fields that we designed and tested as proof-of-concept. These findings underscore the potential and versatility of magnetic SIPNs hydrogels based on carbohydrate biopolymers as fundamental components in driving the progress of advanced hydrogels for diverse practical implementations.

In vitro and in vivo investigation of chitosan/silk fibroin injectable interpenetrating network hydrogel with microspheres for cartilage regeneration.

Articular cartilage is an avascular and almost acellular tissue with limited self-regenerating capabilities. Although injectable hydrogels have garnered a lot of attention as a promising treatment, a biocompatible hydrogel with adequate mechanical properties is yet to be created. In this study, an interpenetrating network hydrogel comprised of chitosan and silk fibroin was created through electrostatic and hydrophobic bonds, respectively. The polymeric network of the scaffold combined an effective microenvironment for cell activity with enhanced mechanical properties to address the current issues in cartilage scaffolds. Furthermore, microspheres (MS) were utilized for a controlled release of methylprednisolone acetate (MPA), around ~75 % after 35 days. The proposed scaffolds demonstrated great mechanical stability with ~0.047 MPa compressive moduli and ~145 kPa compressive strength. Moreover, the degradation rate of the samples (~45 % after 35 days) was optimized to match neo-cartilage formation. Furthermore, the use of natural biomaterials yielded good biocompatibility with ~76 % chondrocyte viability after 7 days. According to gross observation after 12 weeks the defect site of the treated groups was filled with minimally discernible boundary. These results were confirmed by histopathology assays were the treated groups showed higher chondrocyte count and collagen type II expression.