Soft Tissue Applications Research Articles

Electrospinning and melt electrowriting of a tunable triblock-copolymer composed of poly(ε-caprolactone) and poly(L-lactic acid) for biomedical applications

Both electrospinning (ES) and melt electrowriting (MEW) garner emerging interest within the field of biomedical applications. Poly(ε-caprolactone) (PCL) is still the gold standard for both techniques, demonstrating excellent processability due to its solubility, melt flow properties and thermal stability. However, when evaluating biomaterials for soft tissue applications, PCL exhibits limitations such as low elasticity and extended biodegradation times. Additionally, the limited availability of materials that are processable by MEW constrains their broader clinical translation. To address this limitation, a tunable triblock-copolymer of PCL and poly(L-lactic acid) (PLLA) is synthesized and processed using ES and MEW. This synthesis employs a PCL-diol backbone with a molar mass of 30 000 g mol-1, to which various lengths of PLLA end-blocks are added on both termini (PLLA-b-PCL-b-PLLA). The successful incorporation of these tunable end-blocks is verified through spectroscopic analysis. The ES of PLLA-b-PCL-b-PLLA reveals excellent fiber formation, with fiber diameters ranging between 2–4 µm as the PLLA molar mass increases. The tunable nature of the polymer allows for MEW at 90 °C, producing fibers with diameters ranging between 40–50 µm. Additionally, the materials exhibit adjustable mechanical properties and biodegradation rates by varying the PLLA segment lengths. Finally, in vitro cell testing using MC3T3-E1 cells demonstrates the polymer's excellent biocompatibility.

Versatile Mechanically Tunable Hydrogels for Therapeutic Delivery Applications.

Hydrogels provide a versatile platform for biomedical material fabrication that can be structurally and mechanically fine-tuned to various tissues and applications. Applications of hydrogels in biomedicine range from highly dynamic injectable hydrogels that can flow through syringe needles and maintain or recover their structure after extrusion to solid-like wound-healing patches that need to be stretchable while providing a selective physical barrier. In this study, a toolbox is designed using thermo-responsive poly(N-isopropylacrylamide) (PNIPAM) polymeric matrices and nanocelluloses as reinforcing agent to obtain biocompatible hydrogels with altering mechanical properties, from a liquid injectable to a solid-like elastic hydrogel. The liquid hydrogels possess low viscosity and shear-thinning properties at 25 °C, which allows facile injection at room temperature, while they become viscoelastic gels at body temperature. In contrast, the covalently cross-linked solid-like hydrogels exhibit enhanced viscoelasticity. The liquid hydrogels are biocompatible and are able to delay the in vitro release and maintain the bioactivity of model drugs. The antimicrobial agent loaded solid-like hydrogels are effective against typical wound-associated pathogens. This work presents a simple method of tuning hydrogel mechanical strength to easily adapt to applications in different soft tissues and broaden the potential of renewable bio-nanoparticles in hybrid biomaterials with controlled drug releasecapabilities.

Evaluation of acoustic-thermal simulations of invivo magnetic resonance guided focused ultrasound ablative therapy.

To evaluate numerical simulations of focused ultrasound (FUS) with a rabbit model, comparing simulated heating characteristics with magnetic resonance temperature imaging (MRTI) data collected during invivo treatment. A rabbit model was treated with FUS sonications in the biceps femoris with 3D MRTI collected. Acoustic and thermal properties of the rabbit muscle were determined experimentally. Numerical models of the rabbits were created, and tissue-type-specific properties were assigned. FUS simulations were performed using both the hybrid angular spectrum (HAS) method and k-Wave. Simulated power deposition patterns were converted to temperature maps using a Pennes' bioheat equation-based thermal solver. Agreement of pressure between the simulation techniques and temperature between the simulation and experimental heating was evaluated. Contributions of scattering and absorption attenuation were considered. Simulated peak pressures derived using the HAS method exceeded the simulated peak pressures from k-Wave by 1.6 ± 2.7%. The location and FWHM of the peak pressure calculated from HAS and k-Wave showed good agreement. When muscle acoustic absorption value in the simulations was adjusted to approximately 54% of the measured attenuation, the average root-mean-squared error between simulated and experimental spatial-average temperature profiles was 0.046 ± 0.019 °C/W. Mean distance between simulated and experimental COTMs was 3.25 ± 1.37 mm. Transverse FWHMs of simulated sonications were smaller than in invivo sonications. Longitudinal FWHMs were similar. Presented results demonstrate agreement between HAS and k-Wave simulations and that FUS simulations can accurately predict focal position and heating for invivo applications in soft tissue.

A Covalently Cross-Linked Hyaluronic Acid/Carboxymethyl Cellulose Composite Hydrogel as a Potential Filler for Soft Tissue Augmentation.

The use of fillers for soft tissue augmentation is an approach to restore the structure in surgically or traumatically created tissue voids. Hyaluronic acid (HA), is one of the main components of the extracellular matrix, and it is widely employed in the design of materials with features similar to human tissues. HA-based fillers already find extensive use in soft tissue applications, but are burdened with inherent drawbacks, such as poor thermal stability. A well-known strategy to improve the HA properties is to reticulate it with 1,4-Butanediol diglycidyl ether (BDDE). The aim of this work was to improve the design of HA hydrogels as fillers, by developing a crosslinking HA method with carboxymethyl cellulose (CMC) by means of BDDE. CMC is a water soluble cellulose ether, whose insertion into the hydrogel can lead to increased thermal stability. HA/CMC hydrogels at different ratios were prepared, and their rheological properties and thermal stability were investigated. The hydrogel with an HA/CMC ratio of 1/1 resulted in the highest values of viscoelastic moduli before and after thermal treatment. The morphology of the hydrogel was examined via SEM. Biocompatibility response, performed with the Alamar blue assay on fibroblast cells, showed a safety percentage of around 90% until 72 h.

Comparing fully automated AI body composition measures derived from thin and thick slice CT image data.

To compare fully automated artificial intelligence body composition measures derived from thin (1.25mm) and thick (5mm) slice abdominal CT data. In this retrospective study, fully automated CT-based body composition algorithms for quantifying bone attenuation, muscle attenuation, muscle area, liver attenuation, liver volume, spleen volume, visceral-to-subcutaneous fat ratio (VSR) and aortic calcium were applied to both thin (1.25 × 0.625mm) and thick (5 × 3mm) abdominal CT series from two patient cohorts: unenhanced scans in asymptomatic adults undergoing colorectal cancer screening, and post-contrast scans in patients with colorectal cancer. Body composition measures derived from thin and thick slice data were compared, including correlation coefficients and Bland-Altman analysis. A total of 9882 CT scans (mean age, 57.0years; 4527 women, 5355 men) were evaluated, including 8947 non-contrast and 935 contrast-enhanced CT exams. Very strong positive correlation was observed for all soft tissue measures: muscle attenuation (r2 = 0.97), muscle area (r2 = 0.98), liver attenuation (r2 = 0.99), liver volume (r2 = 0.98) and spleen volume (r2 = 0.99), VSR (r2 = 0.98), and aortic calcium (r2 = 0.92); (p < 0.001 for all). Moderate positive correlation was observed for bone attenuation (r2 = 0.35). Bland-Altman analysis showed strong agreement for muscle attenuation, muscle area, liver attenuation, liver volume and spleen volume. Mean percentage differences amongst body composition measures were less than 5% for VSR (4.6%), muscle area (-0.5%), liver attenuation (0.4%) and liver volume (2.7%) and less than 10% for muscle attenuation (-5.5%) and spleen volume (5.1%). For aortic calcium, thick slice overestimated for Agatston scores between 0 and 100 and > 400 burden in 3.1% and 0.3% relative to thin slice, respectively, but underestimated scores between 100 and 400. Automated body composition measures derived from thin and thick abdominal CT data are strongly correlated and show agreement, particularly for soft tissue applications, making it feasible to use either series for these CT-based body composition algorithms.

Bioactive-Loaded Hydrogels Based on Bacterial Nanocellulose, Chitosan, and Poloxamer for Rebalancing Vaginal Microbiota.

Biocompatible drug-delivery systems for soft tissue applications are of high interest for the medical and pharmaceutical fields. The subject of this research is the development of hydrogels loaded with bioactive compounds (inulin, thyme essential oil, hydro-glycero-alcoholic extract of Vitis vinifera, Opuntia ficus-indica powder, lactic acid, citric acid) in order to support the vaginal microbiota homeostasis. The nanofibrillar phyto-hydrogel systems developed using the biocompatible polymers chitosan (CS), never-dried bacterial nanocellulose (NDBNC), and Poloxamer 407 (PX) incorporated the water-soluble bioactive components in the NDBNC hydrophilic fraction and the hydrophobic components in the hydrophobic core of the PX fraction. Two NDBNC-PX hydrogels and one NDBNC-PX-CS hydrogel were structurally and physical-chemically characterized using Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), and rheology. The hydrogels were also evaluated in terms of thermo-responsive properties, mucoadhesion, biocompatibility, and prebiotic and antimicrobial effects. The mucin binding efficiency of hydrogel base systems was determined by the periodic acid/Schiff base (PAS) assay. Biocompatibility of hydrogel systems was determined by the MTT test using mouse fibroblasts. The prebiotic activity was determined using the probiotic strains Limosilactobacillus reuteri and Lactiplantibacillus plantarum subsp. plantarum. Antimicrobial activity was also assessed using relevant microbial strains, respectively, E. coli and C. albicans. TEM evidenced PX micelles of around 20 nm on NDBNC nanofibrils. The FTIR and XRD analyses revealed that the binary hydrogels are dominated by PX signals, and that the ternary hydrogel is dominated by CS, with additional particular fingerprints for the biocompounds and the hydrogel interaction with mucin. Rheology evidenced the gel transition temperatures of 18-22 °C for the binary hydrogels with thixotropic behavior and, respectively, no gel transition, with rheopectic behavior for the ternary hydrogel. The adhesion energies of the binary and ternary hydrogels were evaluated to be around 1.2 J/m2 and 9.1 J/m2, respectively. The hydrogels exhibited a high degree of biocompatibility, with the potential to support cell proliferation and also to promote the growth of lactobacilli. The hydrogel systems also presented significant antimicrobial and antibiofilm activity.

Opportunities for Bioactive Glass in Gastrointestinal Conditions: A Review of Production Methodologies, Morphology, Composition, and Performance.

Bioactive glasses (BGs) are widely used in orthopedic and dental applications for their ability to stimulate endogenous bone formation and regeneration. BG applications more recently broadened to include soft tissue conditions, based on their ability to stimulate angiogenesis, soft tissue regeneration, and wound healing. Sol-gel synthesis has helped facilitate this expansion, allowing formulators to tailor the morphological characteristics of the BG matrix. The effectiveness of BGs in skin wound healing is viewed as a gateway for their use as both a therapeutic and drug delivery platform in other soft tissue applications, notably gastrointestinal (GI) applications, which form the focus of this review. Recent changes in international guidelines for GI conditions shifted clinical objectives from symptom management to mucosal wound healing. The additional scrutiny of proton pump inhibitor (PPI) safety, increasing burden of disease, and financial costs associated with gastroesophageal reflux disease (GERD), peptic ulcer disease (PUD), and inflammatory bowel disease (IBD) open new clinical possibilities for BG. This narrative literature review intersects materials engineering, formulation science, and clinical practice, setting it apart from prior literature. Broadly, current evidence for BG applications in GI conditions is sparse and under-developed, which this review directly addresses. It explores and synthesizes evidence that supports the potential use of sol-gel-derived BG for the efficacious treatment of soft tissue applications, with specific reference to GI conditions. An overview with comparative analysis of current BG synthesis techniques and associated challenges is presented, and influences of composition, biologically active ions, and morphological characteristics in soft tissue applications are explored. To contextualize this, sol-gel-derived BGs are proposed as a dual, tailorable therapeutic and drug delivery platform for upper and lower GI conditions. Future directions for this largely untapped area of translational research are also proposed, based on extant literature.

Laser Vaporization of Mouth Lesions, an Overview

Lasers are utilized in dentistry as a therapeutic tool or as an auxiliary tool. The major purpose of employing lasers in dentistry is to overcome the difficulties that are currently observed in traditional dental treatment treatments. The laser is used in hard tissue applications such as caries prevention, bleaching, restorative removal and curing, cavity preparation, dentinal hypersensitivity, growth modulation, and diagnostics, whereas soft tissue applications include wound healing, removal of hyperplastic tissue to uncover impacted or partially erupted teeth, photodynamic therapy for malignancies, and photo-stimulation of herpetic lesions. Lasers' capacity to perform minimally invasive operations with minimum patient discomfort has proven effective in the patient delivery system in dentistry practice. The availability of lasers with various wavelengths has produced a surgical panacea, and laser technology has replaced traditional surgical techniques in many oral surgical operations.

Hybrid 3D-Printed and Electrospun Scaffolds Loaded with Dexamethasone for Soft Tissue Applications.

To make the regenerative process more effective and efficient, tissue engineering (TE) strategies have been implemented. Three-dimensional scaffolds (electrospun or 3D-printed), due to their suitable designed architecture, offer the proper location of the position of cells, as well as cell adhesion and the deposition of the extracellular matrix. Moreover, the possibility to guarantee a concomitant release of drugs can promote tissue regeneration. A PLA/PCL copolymer was used for the manufacturing of electrospun and hybrid scaffolds (composed of a 3D-printed support coated with electrospun fibers). Dexamethasone was loaded as an anti-inflammatory drug into the electrospun fibers, and the drug release kinetics and scaffold biological behavior were evaluated. The encapsulation efficiency (EE%) was higher than 80%. DXM embedding into the electrospun fibers resulted in a slowed drug release rate, and a slower release was seen in the hybrid scaffolds. The fibers maintained their nanometric dimensions (less than 800 nm) even after deposition on the 3D-printed supports. Cell adhesion and proliferation was favored in the DXM-loading hybrid scaffolds. The hybrid scaffolds that were developed in this study can be optimized as a versatile platform for soft tissue regeneration.

Self-Standing 3D-Printed PEGDA-PANIs Electroconductive Hydrogel Composites for pH Monitoring.

Additive manufacturing (AM), or 3D printing processes, is introducing new possibilities in electronic, biomedical, sensor-designing, and wearable technologies. In this context, the present work focuses on the development of flexible 3D-printed polyethylene glycol diacrylate (PEGDA)- sulfonated polyaniline (PANIs) electrically conductive hydrogels (ECHs) for pH-monitoring applications. PEGDA platforms are 3D printed by a stereolithography (SLA) approach. Here, we report the successful realization of PEGDA-PANIs electroconductive hydrogel (ECH) composites produced by an in situ chemical oxidative co-polymerization of aniline (ANI) and aniline 2-sulfonic acid (ANIs) monomers at a 1:1 equimolar ratio in acidic medium. The morphological and functional properties of PEGDA-PANIs are compared to those of PEGDA-PANI composites by coupling SEM, swelling degree, I-V, and electro-chemo-mechanical analyses. The differences are discussed as a function of morphological, structural, and charge transfer/transport properties of the respective PANIs and PANI filler. Our investigation showed that the electrochemical activity of PANIs allows for the exploitation of the PEGDA-PANIs composite as an electrode material for pH monitoring in a linear range compatible with that of most biofluids. This feature, combined with the superior electromechanical behavior, swelling capacity, and water retention properties, makes PEGDA-PANIs hydrogel a promising active material for developing advanced biomedical, soft tissue, and biocompatible electronic applications.

Development by emulsion templating of a novel Tunisian clay-polyvinyl alcohol/extra-virgin olive oil scaffold with antibiofilm properties

A biobased porous scaffold with antibacterial and antioxidant properties was developed using the emulsion templating method. This technique represents a new route for the development of porous materials with controllable pore size. To take into account the environmental and economic aspects, polyvinyl alcohol (PVA) was chosen as the polymer matrix, raw Tunisian clay as the Pickering emulsion stabilizer, and extra virgin olive oil (EVOO) as the oil phase. PVA is often chosen for producing wound dressings that create a moist environment and consequently promote healing. Clay was used as a barrier against bacteria and as emulsifier due to its nanoscale and layered structure. In EVOO, the polyphenolic compounds have antioxidant activity and fatty acids have a plasticizer role. X-ray fluorescence, X-ray diffraction and Fourier transform infrared spectroscopy were used to analyze the raw clay. Then, the obtained films were structurally and chemically characterized, and their performance, antimicrobial activity against Pseudomonas aeruginosa, and antioxidant activity were evaluated. The emulsion characterization showed that clay addition influenced the emulsion type and increased the emulsion stability index to 98%, even after 3 months of storage. This was explained by the irreversible adsorption of clay platelets on the droplet surface that formed a rigid shell to prevent coalescence. The film characterization demonstrated that the oil: water ratio did not influence the surface porosity, although it affected the pore size uniformity and interconnection. Conversely, shortening the curing time improved the surface porosity. The resulting PVA-clay/EVOO scaffold displayed an exceptional performance, including high mechanical strength (∼2.1 MPa), interconnected porous structure with a size ranging from few µm to > 30 µm, and hydrophobic properties (∼90° ± 2). In addition, it showed antiadhesive and antibiofilm activities against P. aeruginosa. Therefore, this scaffold could be used for the early prevention of biofilm formation during wound healing and is a promising candidate for the controlled release of drugs and potentially for various applications in soft tissues.

Nanocomposite Hydrogels with Polymer Grafted Silica Nanoparticles, Using Glucose Oxidase.

Nanocomposite hydrogels offer remarkable potential for applications in bone tissue engineering. They are synthesized through the chemical or physical crosslinking of polymers and nanomaterials, allowing for the enhancement of their behaviour by modifying the properties and compositions of the nanomaterials involved. However, their mechanical properties require further enhancement to meet the demands of bone tissue engineering. Here, we present an approach to improve the mechanical properties of nanocomposite hydrogels by incorporating polymer grafted silica nanoparticles into a double network inspired hydrogel (gSNP Gels). The gSNP Gels were synthesised via a graft polymerization process using a redox initiator. gSNP Gels were formed by grafting 2-acrylamido-2-methylpropanesulfonic acid (AMPS) as the first network gel followed by a sequential second network acrylamide (AAm) onto amine functionalized silica nanoparticles (ASNPs). We utilized glucose oxidase (GOx) to create an oxygen-free atmosphere during polymerization, resulting in higher polymer conversion compared to argon degassing. The gSNP Gels showed excellent compressive strengths of 13.9 ± 5.5 MPa, a strain of 69.6 ± 6.4%, and a water content of 63.4% ± 1.8. The synthesis technique demonstrates a promising approach to enhance the mechanical properties of hydrogels, which can have significant implications for bone tissue engineering and other soft tissue applications.

Microstructural and micromechanical modeling of gum-gelatin-based soft tissue engineering scaffolds

Oral and dental diseases, including periodontal disease, are among the most common conditions in the field of dentistry. The best treatment for this complication is the use of different polymers and multi-component biological tissue prepared through the freeze-drying technique. In this study, biocompatible and biodegradable polymers, namely polyvinyl alcohol (PVA) and gelatin (GN), were used for this purpose, along with Arabian gum-hydroxyapatite (HA) for its antibacterial properties. Arabian gum, with weight percentages of 0, 2, 4, and 6 wt%, was added to the polyvinyl alcohol-gelatin composition at −55 °C for 28 h in the freezer and 48 h at −45 °C under a pressure of 0.01 mbar. The resulting porous biological tissue, with four different ratios, was tested for mechanical and biological analysis in a physiological solution. Then, the samples were analyzed using a scanning electron microscope (SEM) and X-ray diffraction (XRD) technique to study the morphology and structure of the compounds before and after placement in biological solutions. Additionally, a wettability and antibacterial test were performed on the nanocomposite specimen. The SEM observations reveal that this method can create a porous structure with a porosity of about 30–50 μm with a spherical and circular architecture, which was further improved by the addition of gum, reducing the percentage of porosity and improving the tissue's tensile strength and elastic modulus. The porosity changes showed a decrease from 72 % to 60 %, and the tensile strength increased from 53.5 kPa to 76 kPa, resulting in an elastic modulus of 510 kPa to 800 kPa. The addition of gum also reduced the rate of destruction of the biological tissue, making it more suitable for soft tissue applications. The obtained results of the pH test showed that the concentration changes were neutral. The contact angle of water droplets was measured to determine hydrophilicity, indicating an improvement in hydrophilicity after the addition of gum. The results showed that the use of PVA and gelatin, due to their ductility and suitable mechanical properties, along with Arabian gum-HA, could accelerate the healing process of dental periodontal problems.

Development of a More Environmentally Friendly Silk Fibroin Scaffold for Soft Tissue Applications.

A push for environmentally friendly approaches to biomaterials fabrication has emerged from growing conservational concerns in recent years. Different stages in silk fibroin scaffold production, including sodium carbonate (Na2CO3)-based degumming and 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP)-based fabrication, have drawn attention for their associated environmental concerns. Environmentally friendly alternatives have been proposed for each processing stage; however, an integrated green fibroin scaffold approach has not been characterized or used for soft tissue applications. Here, we show that the combination of sodium hydroxide (NaOH) as a substitute degumming agent with the popular "aqueous-based" alternative silk fibroin gelation method yields fibroin scaffolds with comparable properties to traditional Na2CO3-degummed aqueous-based scaffolds. The more environmentally friendly scaffolds were found to have comparable protein structure, morphology, compressive modulus, and degradation kinetics, with increased porosity and cell seeding density relative to traditional scaffolds. Human adipose-derived stem cells showed high viability after three days of culture while seeded in each scaffold type, with uniform cell attachment to pore walls. Adipocytes from human whole adipose tissue seeded into scaffolds were found to have similar levels of lipolytic and metabolic function between conditions, in addition to a healthy unilocular morphology. Results indicate that our more environmentally friendly methodology for silk scaffold production is a viable alternative and well suited to soft tissue applications.

Preparation and Characterization of an Electrospun Polycaprolactone/Polyurethane Scaffold for Soft Tissue Applications

In this study, a synthetic scaffold was prepared from polycaprolactone (PCL) and polyurethane (PU) blend, in a ratio of [2:1] [PCL: PU], using electrospinning technique. Electrospun scaffolds from native PCL and PU were also prepared for comparison, using the same polymer concentration 15% weight/ volume w/v. The detailed microstructure and other properties, like mechanical properties, porosity, and contact angle were investigated and compared between the three prepared scaffolds. Then, the survival, adhesion, proliferation and penetration of rat embryonic fibroblast (REF) cells were evaluated on these three prepared scaffolds after being in vitro cultured with these cells for 21 days, using scanning electron microscope (SEM) analysis and histological analysis. The results showed that, all the studied properties, including mechanical properties and contact angle were enhanced by combining PU with PCL in the [PCL: PU] scaffold. The average diameter of fiber and the average size of pore were suitable and proper for cell attachment, cell proliferation, and also the big average pore size in [PCL: PU] scaffold was enough for cell penetration to form a three- dimension 3-D structure, which is the aim of this study.

Laser in Dentistry- A Review

Light Amplification by the Stimulated Emission of Radiation, or LASER, is what the phrase refers to. In 1960, Miaman was the first to apply laser technology on both hard and soft tissues in dentistry. Over the past two decades, laser technology has advanced significantly. Soft tissue applications include wound healing, removal of hyperplastic tissue for uncovering of impacted or partially erupted teeth, photodynamic therapy for malignancies, and photostimulation of herpetic lesion. Various hard tissue applications include caries prevention, bleaching, restorative removal and curing, cavity preparation, dentinal hypersensitivity, growth modulation, and for diagnostic purposes. Although lasers have been shown to be slightly more expensive than conventional therapy, they are a useful tool for improving the effectiveness, specificity, ease, and comfort of dental treatment.

Additive Manufacturing of Polyhydroxyalkanoate-Based Blends Using Fused Deposition Modelling for the Development of Biomedical Devices.

In the last few decades Additive Manufacturing has advanced and is becoming important for biomedical applications. In this study we look at a variety of biomedical devices including, bone implants, tooth implants, osteochondral tissue repair patches, general tissue repair patches, nerve guidance conduits (NGCs) and coronary artery stents to which fused deposition modelling (FDM) can be applied. We have proposed CAD designs for these devices and employed a cost-effective 3D printer to fabricate proof-of-concept prototypes. We highlight issues with current CAD design and slicing and suggest optimisations of more complex designs targeted towards biomedical applications. We demonstrate the ability to print patient specific implants from real CT scans and reconstruct missing structures by means of mirroring and mesh mixing. A blend of Polyhydroxyalkanoates (PHAs), a family of biocompatible and bioresorbable natural polymers and Poly(L-lactic acid) (PLLA), a known bioresorbable medical polymer is used. Our characterisation of the PLA/PHA filament suggest that its tensile properties might be useful to applications such as stents, NGCs, and bone scaffolds. In addition to this, the proof-of-concept work for other applications shows that FDM is very useful for a large variety of other soft tissue applications, however other more elastomeric MCL-PHAs need to be used.

Tough, Transparent, and Slippery PVA Hydrogel Led by Syneresis.

Slippery and transparent polyvinyl alcohol (PVA) hydrogels with mechanical robustness exhibit broad applications in artificial biological soft tissues, flexible wearable electronics, and implantable biomedical devices. Most of the current PVA hydrogels, however, are unable to integrate these features, which compromises its performance in biological and engineering applications. To achieve such purpose, herein, a novel tactic is proposed, salting-out-after-syneresis of PVA, to realize a mechanically robust and highly transparent slippery PVA hydrogel. The syneresis of PVA sol is first conducted to form highly dense and transparent PVA polymer networks, then the salting-out effect tunes the aggregation of the polymer chains to rapidly induce the phase separation and crystallization. The resultant hydrogels show the transparency up to 98% in the visible region, the tribological coefficient down to 0.0081, and the excellent mechanical properties with strength, modulus, and toughness of 26.72±1.05, 6.66±0.29MPa, and 55.21±1.62MJm-3 , respectively. To reveal the potentials, PVA contact lens that combine remarkable lubrication, anti-protein adhesion, biocompatibility, and drug-loading functions are demonstrated. This strategy provides a simple and new avenue for developing the mechanically robust, transparent, and hydrated hydrogels, showing the potential in biomedicine and wearable devices.

The Use of Lasers in Pediatric Dentistry: Applications, Benefits, and Limitations

The application of laser technology in pediatric dentistry holds immense promise for improving the quality of care and treatment experiences for young patients. Laser technology offers efficient methods for diagnosing and addressing oral and dental issues in children, encompassing both soft and hard tissues. Research indicates that the use of lasers in restorative, pulpal, and surgical procedures enhance children's cooperation and results in better care quality. Different kinds of lasers, including laser fluorescence (LF), argon lasers, erbium lasers, and CO2 lasers, are used in a range of dental applications, such as identifying, preventing, and treating cavities, as well as performing various other dental procedures. Laser technology also offers benefits in endodontics, soft tissue applications, trauma management, pain relief, and orthodontics. However, the implementation of lasers requires specialized training, initial investment costs, and careful infection control measures. Despite these limitations, lasers hold the potential to become a standard approach in pediatric dentistry, revolutionizing the way oral and dental issues are diagnosed and treated in young patients.

Gelatin and Bioactive Glass Composites for Tissue Engineering: A Review.

Nano-/micron-sized bioactive glass (BG) particles are attractive candidates for both soft and hard tissue engineering. They can chemically bond to the host tissues, enhance new tissue formation, activate cell proliferation, stimulate the genetic expression of proteins, and trigger unique anti-bacterial, anti-inflammatory, and anti-cancer functionalities. Recently, composites based on biopolymers and BG particles have been developed with various state-of-the-art techniques for tissue engineering. Gelatin, a semi-synthetic biopolymer, has attracted the attention of researchers because it is derived from the most abundant protein in the body, viz., collagen. It is a polymer that can be dissolved in water and processed to acquire different configurations, such as hydrogels, fibers, films, and scaffolds. Searching "bioactive glass gelatin" in the tile on Scopus renders 80 highly relevant articles published in the last ~10 years, which signifies the importance of such composites. First, this review addresses the basic concepts of soft and hard tissue engineering, including the healing mechanisms and limitations ahead. Then, current knowledge on gelatin/BG composites including composition, processing and properties is summarized and discussed both for soft and hard tissue applications. This review explores physical, chemical and mechanical features and ion-release effects of such composites concerning osteogenic and angiogenic responses in vivo and in vitro. Additionally, recent developments of BG/gelatin composites using 3D/4D printing for tissue engineering are presented. Finally, the perspectives and current challenges in developing desirable composites for the regeneration of different tissues are outlined.