Composite Scaffolds Research Articles

FORMULATION, CHARACTERIZATION AND OPTIMIZATION OF PLGA-CHITOSAN-LOADED FATTY ACID SCAFFOLDS FOR THE TREATMENT OF DIABETIC WOUNDS

Objective: The objective of the current research to formulate Eicosapentanoic Acid/Decosahexanoic Acid (EPA/DHA)incorporated into Chitosan (CS)and Poly-Lactic-Glycolic Acid (PLGA), nanoparticles composite scaffolds to the accelerated diabetic wound healing. The main focus of this present research is to evaluate and develop the chitosan–PLGA biodegradable polymer scaffolds loaded with long-chain omega-3 Polyunsaturated Fatty Acids (PUFA’s) (EPA/DHA). Methods: Nano scaffolds were prepared by solvent evaporation method loaded with CS-PLGA, EPA and DHA to treat diabetic wounds at targeted site as pharmacotherapeutically. Upon investigation, the developed biodegradable crosslinked scaffold possesses matrix degradation, optimal porosity, prolonged drug release action than the non-cross linked scaffold. The prepared formulation containing CS-PLGA loaded with EPA/DHA were formulated as nanoscaffold for wound topical applications was carried out by using freeze drying process. Results: The prepared CS-PLGA nano scaffolds were optimized and evaluated for physicochemical properties, dynamic light scattering with a particle size of 248 nm and zeta of-24mVand Scanning Electron Microscopy (SEM) were found to be spherical. In addition, the optical properties of EPA/DHA and PLGA, along with CS, can be compared by examining their absorption and wavelength (nm) using UV-visible spectroscopy. The structural and functional groups of the prepared end products were characterized by Fourier-Transformed Infrared Spectroscopy (FT-IR) has shown good compatibility with excipients and nanoformulaton, in vitro drug release studies done by using dialysis bag membrane results find that first-order Higuchi model was followed showing 20% release in first 0.2 h. MTT(3-(4,5-dimethylthiazolyl)-2,5-diphenyltetrazolium bromide) assay was carried out and it showed that both crosslinked and non-crosslinked scaffolds(110 and 120%) improved cell growth when compared to control (100%). Conclusion: Finally, the results showed that the PLGA, CS nanoscaffolds containing 98% of PUFA’s (EPA/DHA) have increased in proinflammatory cytokines production at the particular wound site and thus accelerated healing activity, depending on the pre-clinical studies have trespassed, the therapeutic potential to penetrating at wound site. The optimized nanoformulation could be a better formulation for targeting and treatment of diabetic wounds at an optimal ratio.

Composite Scaffold Materials of Nanocerium Oxide Doped with Allograft Bone: Dual Optimization Based on Anti-Inflammatory Properties and Promotion of Osteogenic Mineralization.

Spinal fusion technique is widely used in the treatment of lumbar degeneration, cervical instability, disc injury, and spinal deformity. However, it is usually accompanied by a high incidence of fusion failure and pseudoarthrosis, placing higher demands on bone implants. Therefore, materials with good biocompatibility, osteoconductivity, and even induce bone ingrowth, which can be used to improve spinal fusion rate and bone regeneration, have become a hot research topic. Here, ultra-small cerium oxide nanoparticles (CeO2 NPs) are prepared and loaded onto the surface of the homograft bone surface to prepare a composite scaffold AB@PLGA/CeO2. The composite scaffold shows the competitive ability to promote osteoblast differentiation in vitro. In vivo experiments show that AB@PLGA/CeO2 has a good bone enhancement effect. In particular, good biological effects of collagen fiber formation, osteogenic mineralization, and tissue repair are shown in intervertebral implant fusion. Further, transcriptome sequencing confirms that CeO2 NPs promote osteogenic differentiation and mineralization by regulating extracellular matrix (ECM) and collagen formation. Meanwhile, CeO2 NPs can regulate the function of the PI3K-Akt signaling pathway to exert its ability to promote osteogenic differentiation and mineralization and affect p53 and cell cycle signaling pathway to regulate osteogenic differentiation and mineralization. Hence, the proposed scaffold is a promising strategy for intervertebral fusion in the clinic.

Decellularized Extracellular Matrix Scaffolds: Recent Advances and Emerging Strategies in Bone Tissue Engineering.

Bone tissue engineering (BTE) is a complex biological process involving the repair of bone tissue with proper neuronal network and vasculature as well as bone surrounding soft tissue. Synthetic biomaterials used for BTE should be biocompatible, support bone tissue regeneration, and eventually be degraded in situ and replaced with the newly generated bone tissue. Recently, various forms of bone graft materials such as hydrogel, nanofiber scaffolds, and 3D printed composite scaffolds have been developed for BTE application. Decellularized extracellular matrix (DECM), a kind of natural biological material obtained from specific tissues and organs, has certain advantages over synthetic and exogenous biomaterial-derived bone grafts. Moreover, DECM can be developed from a wide range of biological sources and possesses strong molding abilities, natural 3D structures, and bioactive factors. Although DECM has shown robust osteogenic, proangiogenic, immunomodulatory, and bone defect healing potential, the rapid degradation and limited mechanical properties should be improved for bench-to-bed translation in BTE. This review summarizes the recent advances in DECM-based BTE and discusses emerging strategies of DECM-based BTE.

Incorporating Hydrogel (with Low Polymeric Content) into 3D-Printed PLGA Scaffolds for Local and Sustained Release of BMP2 in Repairing Large Segmental Bone Defects.

Treating large bone defects remains a considerable challenge for clinicians: bone repair requires scaffolds with mechanical properties and bioactivities. Herein, based on crosslinking o-phthalaldehyde (OPA) with amine groups, 4-arm polyethylene glycol (4armPEG)-OPA/Gelatin hydrogel loaded with bone morphogenetic protein 2 (BMP2) is prepared and a three dimensional (3D)-printed poly (lactic-co-glycolic acid) (PLGA) porous scaffold is filled with the hydrogel solution. The composite scaffold, with a compression modulus of 0.68 ±0.097GPa similar to the cancellous bone, has a porosity of 56.67 ± 4.72% and a pore size of about 380µm, promoting bone growth. The hydrogel forms a porous network at low concentrations, aiding protein release and cell migration. The hydrogel degrades in approximately three weeks, and the scaffold takes five months, matching bone repair timelines. BMP2 release experiment shows a sustained BMP2 release with a 72.4 ± 0.53% release ratio. The ALP activity test and alizarin red staining shows effective osteogenic promotion, while RT-PCR confirms BMP2@Gel enhanced COL-1 and OPN expression. Animal experiments further validate the composite scaffold's bone repair efficacy. This study demonstrates the effectiveness of the hydrogel in releasing BMP2 and the mechanical support of the 3D-printed PLGA porous scaffold, providing a new treatment for bone defects.

Sodium alginate hydrogels co-encapsulated with cell free fat extract-loaded core-shell nanofibers and menstrual blood stem cells derived exosomes for acceleration of articular cartilage regeneration

This study presents a novel scaffold system comprising sodium alginate hydrogels (SAh) co-encapsulated with cell-free fat extract (CEFFE)-loaded core-shell nanofibers (NFs) and menstrual blood stem cell-derived exosomes (EXOs). The scaffold integrates the regenerative potential of EXOs and CFFFE, offering a multifaceted strategy for promoting articular cartilage repair. Coaxially electrospun core-shell NFs exhibited successful encapsulation of CEFFE and seamless integration into the SAh matrix. Structural modifications induced by the incorporation of CEFFE-NFs enhanced hydrogel porosity, mechanical strength, and degradation kinetics, facilitating cell adhesion, proliferation, and tissue ingrowth. The release kinetics of growth factors from the composite scaffold demonstrated sustained and controlled release profiles, essential for optimal tissue regeneration. In vitro studies revealed high cell viability, enhanced chondrocyte proliferation, and migration in the presence of EXOs/CEFFE-NFs@SAh composite scaffolds. Additionally, in vivo experiments demonstrated significant cartilage regeneration, with the composite scaffold outperforming controls in promoting hyaline cartilage formation and defect bridging. Overall, this study underscores the potential of EXOs and CEFFE-NFs integrated into SAh matrices for enhancing chondrocyte viability, proliferation, migration, and ultimately, articular cartilage regeneration. Future research directions may focus on elucidating underlying mechanisms and conducting long-term in vivo studies to validate clinical applicability and scalability.

All-Natural Ceramic Whitlockite/Wollastonite Fiber Composite Bone Scaffolds: DLP Additive Manufacturing, Microstructure, and Performance

In this study, we introduced a novel approach by using natural calcium phosphate-based ceramic whitlockite as the matrix, natural silicon-based ceramic wollastonite fiber as the secondary phase, and desktop-level DLP 3D printing as the fabrication method to develop an all-natural ceramic porous bone scaffold with excellent mechanical, degradable, biomineralization, and cell responses. The results demonstrated that, at a solid loading of 75 wt% and a sintering temperature of 1000°C, the compressive strength of the whitlockite porous scaffold reached 20.0 MPa. With the incorporation of wollastonite fiber, the compressive strength of the composite ceramic scaffold further increased to 31.0 MPa, achieving a top-tier level for desktop-level DLP-printed porous ceramic bone scaffolds. This mechanical enhancement effect was mainly attributed to the grain refinement effect of WF on whitlockite and the fiber reinforcement effect of WF. Additionally, the degradation rate of the composite ceramic scaffold increased with higher WF content, attributed to the rapid degradation rate of WF and the microstructural changes in the whitlockite matrix induced by WF doping. Furthermore, the biomineralization capability and cellular response of the composite ceramic scaffold were enhanced with WF doping, due to the improved degradation ability promoting the release of calcium, phosphate, and silicon ions. This study further validates the applicability of desktop-level DLP for fabricating ceramic bone scaffolds and provides evidence of the potential of all-natural ceramic whitlockite/WF as bone scaffold materials.

3D printed TC4 titanium alloy bone scaffolds with TNTs-VA-PLGA composite coating on the surface:improved infection resistance and biocompatibility

Titanium-based bone scaffolds are prone to aseptic infection and loosening after implantation,which seriously limits their clinical applications. Preparation of titanium dioxide nanotubes (TNTs) on the surface of the scaffolds and loading of anti-infective drugs is an effective method to solve this problem, but the current TNTs prepared on the surface of titanium-based scaffolds have a high internal and external variability in morphology and low drug loading capacity. In this study, we prepared TNTs on the surface of three kinds of TC4 titanium alloy scaffolds with TPMS structure with controllable morphology, tube diameter of 90-125 nm and tube length of 14-35 μm,and the difference between inner and outer diameters of the tubes was less than 2 μm,and the drug released from the composite scaffolds was maintained at a concentration of more than 1.5 μg/ml within 11 days after loading anti-infective drug Vancomycin-polylactic acid-hydroxyacetic acid copolymer(VA-PLGA) on the surface of the TNTs. Based on the simulation of drug release, the TNTs-VA-PLGA drug delivery system conforms to the Korsmeyer-Peppas model. Cell experiments confirmed that the composite scaffolds significantly increased cell proliferation by 65.33% compared with the unmodified scaffolds. The results indicated that the TNTs coating containing vancomycin and polylactic acid-hydroxyacetic acid copolymer had a promising application in orthopedic implants.

Electrospun Polylactic Acid/Polyethylene Glycol/ Silicate‐Chlorinated Bioactive Glass Composite Scaffolds for Potential Bone Regeneration

ABSTRACTThe integration of bioglass with polymers in tissue engineering scaffolds holds promise for enhancing bone regeneration. This study explores the fabrication and characterization of composite scaffolds comprising polylactic acid (PLA)/polyethylene glycol (PEG) fibers incorporated with silicate‐chlorinated bioglasses (45S5 and 58S). Electrospinning was utilized to produce the scaffolds, followed by physical–chemical and in vitro evaluations. Scanning electron microscopy (SEM) revealed uniform fiber formation, with bioglass incorporation observed in the composite groups. Bioglass incorporation led to a significant reduction in fiber diameter. Thermogravimetric analysis (TGA) estimated bioglass content, with 58S exhibiting the highest incorporation. Contact angle measurements indicated enhanced hydrophilicity in bioglass‐containing groups. In vitro, bioactivity assessment in simulated body fluid (SBF) demonstrated apatite formation potential and the pH variance indicates a slightly alkaline to neutral condition. Cell culture studies revealed robust cellular adhesion and metabolic activity across all groups, with no cytotoxic effects observed. Overall, these findings suggest the potential of PLA/PEG bioglass composite scaffolds for bone tissue engineering applications.

3D-printed porous calcium silicate scaffolds with hydroxyapatite/graphene oxide hybrid coating for guided bone regeneration

Calcium silicate (CS) is a suitable bone repair material due to its bioactivity and biocompatibility. However, its rapid degradation rate and poor cell response affect the bone regeneration process. Surface modification of implants represents a potent strategy for enhancing the performance of biomaterials. Here, we present a novel method combining hydrothermal treatment and chemical grafting to tailor the surface morphology and composition of 3D-printed calcium silicate porous scaffolds. The resulting scaffold surface features hydroxyapatite (HA) nanosheets and graphene oxide (GO) sheet structures. Surface modification significantly reduced the degradation rate of CS scaffolds and decreased the Si ion concentration after PBS immersion, which was more conducive to cell survival. Our findings reveal that the CS/HA/GO scaffold exhibits superior biocompatibility and significantly enhances cell adhesion, proliferation, and osteogenic differentiation. In vivo studies demonstrate that the CS/HA/GO scaffold markedly promotes the regeneration of defective bone tissue. This work highlights the potential of HA and GO coatings on interconnected porous scaffolds to induce bone tissue regeneration, offering a promising strategy for orthopedic applications.

Alginate-gelatin based nanocomposite hydrogel scaffold incorporated with bioactive glass nanoparticles and fragmented nanofibers promote osteogenesis: From design to in vitro studies

The current study proposes fragmented nanofibers of polycaprolactone (FNF) with bioactive glass nanoparticles (nBG) incorporated into a polymeric matrix of alginate-gelatin for the creation of a hydrogel scaffold. Four groups were prepared: control, bioactive glass containing scaffold (BG), fragmented nanofibers with bioactive glass scaffold (FNF(PCL) + BG), and fragmented composite nanofibers scaffold (FNF (PCL + BG)). FNF (PCL + BG) scaffolds revealed a more controlled degradation rate, with approximately 20 % degradation occurring after 28 compared. The FNF(PCL) + BG scaffolds had the highest compressive strength in both dry and wet states. Following 14 days of incubation in simulated body fluid, hydroxyapatite formation had occurred on the surface of scaffolds containing nBG, and after 28 days on other groups tested. Cell studies revealed that the FNF(PCL) + BG scaffolds had superior cell viability without inhibiting cell proliferation. The FNF(PCL) + BG and FNF(PCL + BG) scaffolds had the highest alkaline phosphatase (ALP) activity and FNF(PCL) + BG scaffolds showed to support osteogenic differentiation.

Fabrication of composite RGD-tagged poly(lactic acid)-graphene oxide nanofiber containing bone-forming peptide-3 loaded-dendritic silica nanoparticles for bone regeneration in rabbit

In the current study, polylactic acid (PLA)/graphene oxide (GO) based composite scaffolds were fabricated by electrospinning method and then covalently modified with bone-forming peptide-3 (BFP-3)-loaded thiol-functionalized dendritic mesoporous silica nanoparticles (BFP-3@HS-DMSNs) and RGD. In this regard, PLA electrospinning nanofibers and composite of PLA/GO electrospinning nanofibers containing 0.02, 0.01, 0.04, 0.1, 0.2 % of GO were prepared and characterized in terms of mechanical strength, nanofibers diameter, thermal stability, crystallinity, specific surface area, total pore volume and cell adhesion properties. Among the prepared composites, PLA nanofibers containing 0.02 % GO demonstrated superior mechanical and morphological characteristics along with better cell adhesion for mesenchymal stem cell. Then, the PLA/0.02 %GO nanofiber was treated with plasma and consequently modified with N-(2-aminoethyl)maleimide linker which was applied for Cys-RGD and BFP-3@HS-DMSNs conjugation. The obtained results showed desirable adhesion of PLA/0.02 %GO nanofiber after incorporation of RGD (5 % of maleimide groups of the linker) and DMSNs which significantly increase cell adhesion potency (1.53 folds). By incorporation of BFP-3@HS-DMSNs (equivalent to 0.1 µg of BFP-3) to the RGD-tagged PLA/0.02 %GO nanofiber, the scaffold demonstrated better cytocompatibility and MSC differentiation to osteoblast based on biomineralization assay via alizarin red (4.2 folds) and alkaline phosphatase activity (1.7 folds) tests. In preclinical stage, after skull defect creation in rabbits, 5 treatments groups comprising PLA/0.02 %GO nanofiber, PLA/0.02 %GO/DMSNs, PLA/0.02 %GO/DMSNs/Cys-RGD, PLA/0.02 %GO/BFP-3@DMSNs and PLA/0.02%GO/BFP-3@DMSNs/Cys-RGD were used for bone regeneration in skull defects. After 3 months, the implantation of PLA/0.02GO/BFP-3@DMSNs/Cys-RGD showed higher bone regeneration based on CBCT imaging (18.875 mm2 bone formed area) in comparison with other treatment groups. This hybrid multimodal platform is purposely organized interactive processes which lead to potential bone regeneration.

Optimization of an Affordable and Efficient Skin Allograft Composite with Excellent Biomechanical and Biological Properties Suitable for the Regeneration of Deep Skin Wounds: A Preclinical Study.

Deep skin wounds require grafting with a skin substitute for treatment. Despite many attempts in the development of an affordable and efficient skin substitute, the repair of deep skin wounds still remains challenging. In the current study, we present a 3D sponge composite made from human placenta (a disposable organ) and sodium alginate with exceptional properties for skin tissue engineering applications. Toward this goal, different proportions of alginate (Alg) and decellularized placenta scaffold (DPS) were composited and freeze-dried to generate a 3D sponge with the desired biomechanical and biological features. Comprehensive in vitro, in ovo, and in vivo characterizations were performed to assess the morphology, physical structure, mechanical behaviors, angiogenic potential, and wound healing properties of the composites. Through these analyses, the scaffold with optimal proportions of Alg (50%) and DPS (50%) was found to have superior properties. The optimized scaffold (Alg50/DPS50) was applied to the full-thickness wounds created in rats. Our data revealed that the addition of DPS to the Alg solution caused a significant improvement in the mechanical characteristics of the scaffold. Remarkably, the fabricated composite scaffold exhibited mechanical properties similar to those of native skin tissue. When implanted into the full-thickness wounds, the Alg50/DPS50 composite scaffold promoted angiogenesis, re-epithelialization, and granulation tissue formation, as compared to the group without a scaffold. Overall, our findings underscore the potential value of this hybrid scaffold for enhancing skin wound healing and suggest an Alg50/DPS50 composite for clinical investigations.

Hydrogel composition and mechanical stiffness of 3D bioprinted cell-loaded scaffolds promote cartilage regeneration

ObjectiveTo investigate the impact of different component ratios and mechanical stiffness of the gelatin-sodium alginate composite hydrogel scaffold, fabricated through 3D bioprinting, on the viability and functionality of chondrocytes.MethodsThree different concentrations of hydrogel, designated as low, medium, and high, were prepared. The rheological properties of the hydrogel were characterized to optimize printing parameters. Subsequently, the printability and shape fidelity of the cell-loaded hydrogel scaffolds were statistically evaluated, and the chondrocyte viability was observed. Dynamic mechanical analysis was conducted to measure the modulus, thereby assessing the scaffold’s stiffness. Following a 21-day culture period, RT-PCR, histological staining, and immunostaining were employed to assess chondrocyte activity, chondrosphere aggregates formation, and cartilage matrix production.ResultsBased on rheological analysis, optimal printing temperatures for each group were determined as 27.8°C, 28.5°C, and 30°C. The optimized printing parameters could ensure the molding effect of the scaffolds on the day of printing, with the actual grid area of the scaffolds was close to the theoretical grid area. And the scaffolds exhibited good cell viability (93.24% ± 0.99%, 92.04% ± 1.49%, and 88.46% ± 1.53%). After 7 days of culture, the medium and high concentration groups showed no significant change in grid area compared to the day of printing (p > 0.05), indicating good morphological fidelity. As the hydrogel’s bicomponent ratio increased, both the storage modulus and loss modulus increased, while the loss factor remained relatively constant. The highest number of chondrocytes-formed chondrosphere aggregates in the medium concentration group was observed by light microscopy. RT-PCR results indicated significantly higher expression levels of chondrogenic genes SOX9, Agg, and Col-II in the low and medium concentration groups compared to the high concentration group (p < 0.05). Histological staining results showed that the middle concentration group formed the highest number of typical cartilage lacunae.ConclusionThe aforementioned results indicate that in 3D bioprinted cell-loaded GA-SA composite hydrogel scaffolds, the scaffolds with the composition ratio (10:3) and mechanical stiffness (∼155 kPa) exhibit sustained morphological fidelity, effectively preserve the hyaline phenotype of chondrocytes, and are more conducive to cartilage regeneration.

3D-printed scaffolds with controlled-releasing compounds for ectopic activation of dormant ovarian follicles

Throughout a woman’s reproductive life, hundreds of functioning follicles are activated for development, while thousands of dormant follicles remain in the ovaries. Dormant follicle activation in vitro is an effective clinical strategy for women with fertility needs who suffer from ovarian dysfunction. However, activating dormant follicles in vivo is still a challenge due to difficulties such as delivering stimulators to local sites. Here, we developed a compound-preloaded microporous scaffold by combining three-dimensional (3D) printing techniques with pharmacological activators to support and stimulate the activation and development of primordial follicles. The gelatin/alginate composite scaffolds exhibited exceptional mechanical properties and biological compatibility, effectively supporting the survival of ovarian granulosa cells for more than 7 days, which is essential for oocyte development. Furthermore, the ovarian tissue-scaffold complex successfully survived after transplantation under the mouse kidney capsule, demonstrating its excellent biocompatibility. After pre-mixing widely used clinical activators into the bio-ink, the scaffold had the ability to gradually release the mixture of compounds, effectively activating primordial follicles. By transplanting the ovary-scaffold complex containing activators into the mouse abdominal subcutaneous pocket, dormant follicles could be activated subcutaneously and developed into growing follicles. The number of growing follicles is approximately three times higher compared to the group without activators. In conclusion, by integrating biomaterials, activators, and 3D printing technology, we have developed 3D-printed biological scaffolds that can ectopically support primordial follicle activation and development in vivo. This novel approach could provide a promising strategy for treating ovarian insufficiency and endocrine disorders in the clinic, without the need for in situ ovarian tissue grafting.

Pullulan/Collagen Scaffolds Promote Chronic Wound Healing via Mesenchymal Stem Cells

This study investigated the development of Pullulan/Collagen nanofiber scaffolds integrated with mesenchymal stem cells (MSCs) to enhance chronic wound healing. The combination of these biopolymers aims to optimize the scaffold properties for cell growth, viability, and tissue regeneration. Materials and Methods: Pullulan, Collagen, and Pullulan/Collagen composite nanofibers were fabricated using electrospinning. The fibers were characterized using scanning electron microscopy (SEM) to determine the fiber diameter, and Fourier-transform infrared spectroscopy (FTIR) was employed to assess the molecular interactions. Cell viability was evaluated using MSCs cultured on the scaffolds and apoptosis assays were conducted to assess cell health. Distilled water was used as the solvent to maximize biocompatibility. Results: SEM analysis revealed that Pullulan nanofibers exhibited a larger average diameter (274 ± 20 nm) compared to Collagen fibers (167.03 ± 40.04 nm), while the Pullulan/Collagen composite fibers averaged 280 ± 102 nm. FTIR confirmed the molecular interactions between Pullulan and Collagen. Regarding biocompatibility, the Pullulan/Collagen scaffold demonstrated superior cell viability at 99% compared to 91% for Pullulan alone. Apoptosis assays indicated significantly lower necrosis rates for the composite scaffold (1.29%) than for the Pullulan-only scaffolds (2.35%). Conclusion: The use of distilled water as a solvent played a critical role in increasing cell viability and facilitating healthy proliferation of MSCs without cellular damage. Additionally, the reduced platelet activation and macrophage activity (0.75-fold for both) further supported the biocompatibility of the Pullulan/Collagen scaffold, demonstrating its potential for tissue engineering and chronic wound healing applications.

Hydroxyapatite/Silk Fibroin Composite Scaffold with a Porous Structure and Mechanical Strength Similar to Cancellous Bone by Electric Field-Induced Gel Technology.

Repair and regeneration of bone tissue defects is a multidimensional process that has been highly challenging to date. The artificial bone scaffold materials, which play a core role, still face the conflict that a biofriendly porous structure will reduce the mechanical performance and accelerate degradation. Herein, a multistage porous structured hydroxyapatite (HA)/silk fibroin (SF) composite scaffold (e-HA/SF) was successfully constructed by cleverly utilizing electric field-induced gel technology. The results indicated that the prepared e-HA/SF scaffolds possess biomimetic hierarchical porous structures with a suitable porosity similar to that of cancellous bone. The HA nanocrystals were uniformly encapsulated in the three-dimensional space of the composite scaffold, thus endowing the e-HA/SF composite scaffolds with an enhanced mechanical performance. Notably, the maximum compression stress and Young's modulus of e-HA/SF-2 scaffolds can reach 24.66 ± 0.88 and 28.91 ± 3.19 MPa, respectively, which are equivalent to those of cancellous bone. Such mechanical performance enhancement was previously unattainable through conventional freeze-drying strategies. Moreover, the introduction of bioactive nano-HA can trigger the optimal cell response in both static and dynamic cell culture experiments in vitro. The e-HA/SF composite scaffold developed in this study can better balance the conflict between the porous structure and mechanical and degradation properties of porous scaffolds.

Stereolithography Printing and Mechanical Properties of Polyethylene Glycol Diacrylate/Hexagonal Boron Nitride Ceramic Composites

To enhance the mechanical properties of bioceramic composite bone scaffolds, a composite paste of polyethylene glycol diacrylate (PEGDA) and hexagonal boron nitride (h‐BN) with a solid content of up to 42 wt% was developed in this study. The part was produced using stereolithography (SLA). The SLA printing parameters and material ratios of the paste were optimized through a homogeneous design and mechanical property tests. The results indicate that the single‐line curing width of the PEGDA/h‐BN paste in the XY plane ranged from 172 to 209 μm, while the curing depth of a single layer along the Z‐axis ranged from 99 to 154 μm. Laser power was identified as the primary factor influencing both the width and depth of curing. The compressive strength of the printed sample of PEGDA/h‐BN ceramic composite paste was measured at 222.4 ± 5.6 MPa, which is 61 times greater than the compressive strength of a pure PEGDA structure and comparable to that of cortical bone (100‐230 MPa). Finally, the superior biocompatibility of PEGDA/h‐BN ceramics was confirmed through cytotoxicity experiments. Consequently, PEGDA/h‐BN ceramic composites meet the mechanical properties and biocompatibility requirements necessary for bone tissue applications, indicating promising potential in the field of bone tissue engineering.

Two-Dimensional MXene (Ti3C2Tx)-based Nano-Photosensitizers for Enhanced Photothermal Ablation of Tumor Cells

Cancer remains one of the leading causes of death globally, accounting for approximately one in every six deaths. Traditional cancer therapies, including surgery, chemotherapy, chemoimmunotherapy, and radiation, face numerous challenges and limitations. In this context, we explore the advantages of photothermal therapy (PTT) using two-dimensional (2D) MXene-based nanocomposites for cancer treatment. MXenes, composed of abundant and non-toxic elements, such as titanium (Ti), carbon (C), fluorine (F), and oxygen (O), demonstrate low toxicity and are promising candidates in photothermal cancer therapies. Their ultrathin planar nanostructure, high photothermal conversion efficiency, strong near-infrared (NIR) responsiveness, and chemically modifiable surfaces enhance their therapeutic potential. Recent innovations include the development of folic acid-functionalized Au@c-Ti3C2 nanostructures, a skin-mountable electrostimulation patch (eT-patch), ionic gels containing MXene (Ti3C2Tx), and composite scaffolds made of MXene, collagen, silk fibroin, and quercetin. These MXene-based photosensitive compounds offer efficient targeting and selective treatment of cancer cells, highlighting their significant role in advancing cancer therapies.

RF pulsed plasma modified composite scaffold for enhanced anti-microbial activity and accelerated wound healing

Infected wounds present significant challenges pertaining to healing and often demand administration of strong antibiotics to patients. Also, drug resistant microbes may alter the physiology of wounds to create biofilms, frequently leading to high morbidity and mortality. In this investigation, a biodegradable, microporous composite agarose-chitosan scaffold was fabricated. Furthermore, its surface was modified with diphenyldiselenide deposition, using low pressure pulsed plasma technology. The optimized plasma parameters, viz. 5ON/15OFF (ms) of plasma pulse rate and 80 min of treatment time resulted in scaffolds having enhanced anti-bacterial activity against gram positive microbes like Staphylococcus (S.) aureus and S. epidermidis. The scaffolds were non-toxic to skin cells, as confirmed by the MTT assay. Cell proliferation through plasma treated and native scaffolds was assessed by culturing primary human dermal fibroblasts (HdaF) and human keratinocytes (HaCaT) and visualizing via confocal microscopy. Moreover, in-vivo rat model confirmed accelerated wound healing with plasma treated scaffold (100 % on day 14), as compared to the native scaffold (100 % on day 16) when compared with over-the-counter (OTC) ointment Betadine (100 % on day 12).

A promising pullulan/PLA composite: Influence of pullulan in the scaffolds morphology constructed by 3D printing

AbstractManufacturing three‐dimensional scaffolds with significant rough and porous structures is advantageous in tissue regeneration approaches influencing cell growth. Thus, this work aims to study the effect of using different Pullulan contents (PULL) in the poly(lactic) acid (PLA) matrix for 3D printing scaffolds. PLA composites filler with PULL (5 and 10% wt.) were prepared in a thermokinetic mixer, extruded in a machine, and then used to print samples using a fused deposition modeling (FDM) 3D printer. The prepared filaments and scaffolds were characterized using Field emission scanning electron microscopy (FESEM), Fourier‐transform infrared spectroscopy (FTIR), thermogravimetry analyses (TGA), water contact angle (WCA), differential scanning calorimetry (DSC), and hardness techniques. The insertion of PULL into the PLA matrix influenced the increase in diameter and roughness, and density reduction of the composite filaments compared to pristine PLA. Furthermore, the filler promoted an increase in thermal stability, shore hardness, and the development of promising morphological characteristics for cell growth because the walls of the scaffolds are more robust and have more regular‐sized holes. The scaffold fabrication reinforced with 10% PULL presented high surface roughness (up to 1022% if compared with pristine PLA), and open pores can be confirmed successfully compared to pristine PLA. Thus, the use of PULL as a filler in a PLA matrix guarantees the development of composite scaffolds with improved morphological and hardness properties, which could allow the possibility of future research into the application of the proposed material (10% wt. PULL) as an ecologically correct and biocompatible alternative for application in tissue engineering.