"Injectable platelet-rich fibrin for modelling of mandibular lower border defects in bilateral sagittal split osteotomy".

Despite the remarkable progress in virtual surgical planning in the last few decades, which has made orthognathic surgery results more precise and predictable, there remains an unforeseeable risk of developing mandibular lower border defects after bilateral sagittal split osteotomy (BSSO). These defects can cause visible and palpable irregularities of the lower border of the mandible, thereby worsening the surgical result. The study aimed to evaluate the benefit of injectable platelet-rich fibrin (i-PRF) for contour defect modelling in orthognathic surgery in comparison to conventional orthognathic surgery.

Clinical translation of 3D-printed patient-specific bone implants: a consensus statement.

Background: Extensive defects in long bones, resulting from trauma, disease, or other etiologies, impose significant morbidity on patients and may necessitate amputation, long-term disability, or premature mortality. While 3D-printed, patient-specific implants offer promising regenerative solutions, their clinical implementation remains hindered by regulatory challenges, lack of standardized guidelines, and gaps in translational research. Addressing these barriers is critical to improving patient outcomes and optimizing healthcare resource utilization.

Implementing BMP-7 Chemically Modified RNA for Bone Regeneration with 3D Printable Hyaluronic Acid-Collagen Granular Gels.

Chemically modified RNA (cmRNA) is emerging as a more effective alternative to protein delivery and DNA-based gene therapy. To implement this technology for bone regeneration, a suitable biomaterial functioning as scaffold and delivery system is necessary. This study introduces a 3D printable granular hydrogel consisting of hyaluronic acid and collagen (THA-Col) for the delivery of bone morphogenetic protein (BMP)-7 cmRNA as activated matrix to promote bone healing.

Effect of Tyrosine-Containing Self-Assembling β-Sheet Peptides on Macrophage Polarization and Inflammatory Response.

Self-assembling peptides (SAPs) are fully defined nanobiomaterials offering unprecedented opportunities to control nanostructure and chemical attributes to investigate and manipulate cellular signals. To investigate the influence of chemical and morphological characteristics on inflammatory signaling in native immunity, we designed five β-sheet SAPs: EFEFKFEFK (), EFEFKFEFK (), EFEFKFEFK (), EFEFKFEFK (), and EEFKFEFK () (F: phenylalanine; E: glutamic acid; K: lysine, : tyrosine). The position of tyrosine in the peptide sequence dictated the self-assembly into nanostructures, with all SAPs self-assembling into thin constituent nanofibers with ≈ 3.

Optimized hydrogel viscoelasticity and interlocking patch repair enhance compressive range of motion in injured discs and prevent re-herniation under physiological load in an Ex Vivo model.

Purpose: Evaluate how variations in hydrogels viscoelasticity for nucleus pulposus (NP) replacement affect biomechanical function and re-herniation resistance when combined with a mechanically competent annulus fibrosus (AF) repair technique in an intervertebral disc explant model.

Methods: Bovine caudal discs (n = 48) were divided into three repair groups (each n = 12) and one no-repair group (n = 12). Repair groups were treated with hyaluronic acid-tyramine hydrogel (HA-Tyr) of varying viscosities (low, medium, high), and AF was repaired using a mechanically interlocked patch (iPatch) made of polyethylene terephthalate fibers.

Radical-free photopolymerizable composites of hyaluronic acid and gelatin for tissue engineering.

Photopolymerization is widely used in tissue engineering and biofabrication to pattern specific geometries and modulate physical properties. Commonly employed photochemistries rely on a photoinitiator that generates reactive free radicals when exposed to light, which can lead to cytotoxic effects due to interactions with biomolecules and cellular components. To mitigate these issues, we have developed hyaluronic acid and gelatin derivatives of umbelliferone, which can form dimers thanks to cyclobutene ring formation when exposed to long-wavelength UV light (365 nm).

Hyaluronan composite bioink preserves nucleus pulposus cell phenotype in a stiffness-dependent manner.

Intervertebral disc degeneration is a major cause of neck and back pain, representing a significant global socioeconomic burden. The polysaccharide hyaluronan is key to maintaining disc physiology and mediating disc disease through its structural and biological roles in the nucleus pulposus, a component of the intervertebral disc highly susceptible to degeneration. In this study, we introduce a novel composite bioink designed for extrusion bioprinting of structures resembling the nucleus pulposus.

Bone microphysiological models for biomedical research.

Bone related disorders are highly prevalent, and many of these pathologies still do not have curative and definitive treatment methods. This is due to a complex interplay of multiple factors, such as the crosstalk between different tissues and cellular components, all of which are affected by microenvironmental factors. Moreover, these bone pathologies are specific, and current treatment results vary from patient to patient owing to their intrinsic biological variability.

Effect of molecular weight of tyramine-modified hyaluronan on polarization state of THP-1 and peripheral blood mononuclear cells-derived macrophages.

The immunomodulatory properties of hyaluronan and its derivatives are key to their use in medicine and tissue engineering. In this work we evaluated the capability of soluble tyramine-modified hyaluronan (THA) synthesized from hyaluronan of two molecular weights (low M = 280 kDa and high M = 1640 kDa) for polarization of THP-1 and peripheral blood mononuclear cells (PBMCs)-derived macrophages (MΦs). We demonstrate the polarization effects of the supplemented THA by flow cytometry and bead-based multiplex immunoassay for the THP-1 derived MΦs and by semi-automated image analysis from confocal microscopy, immunofluorescent staining utilizing CD68 and CD206 surface markers, RT-qPCR gene expression analysis, as well as using the enzyme-linked immunosorbent assay (ELISA) for PBMCs-derived MΦs.

The impact of adjuvant antibiotic hydrogel application on the primary stability of uncemented hip stems.

Objectives: To assess the effect of adjuvant antibiotic-loaded hydrogel application on the primary stability of implanted uncemented hip stems.

Design: Biomechanical study.

Setting: An electro-mechanic material test system (#5866, Instron, Norwood, MA, USA) equipped with a 10-kN load cell was used.

Preparation and Characterization of Photo-Cross-Linkable Methacrylated Silk Fibroin and Methacrylated Hyaluronic Acid Composite Hydrogels.

Composite biomaterials with excellent biocompatibility and biodegradability are crucial in tissue engineering. In this work, a composite protein and polysaccharide photo-cross-linkable hydrogel was prepared using silk fibroin methacrylate (SFMA) and hyaluronic acid methacrylate (HAMA). SFMA was obtained by the methacrylation of degummed SF with glycidyl methacrylate (GMA), while HA was methacrylated by 2-aminoethyl methacrylate hydrochloride (AEMA).

Combination of bacteriophages and vancomycin in a co-delivery hydrogel for localized treatment of fracture-related infections.

Fracture-related infections (FRIs), particularly those caused by methicillin-resistant Staphylococcus aureus (MRSA), are challenging to treat. This study designed and evaluated a hydrogel loaded with a cocktail of bacteriophages and vancomycin (1.2 mg/mL).

Rheological Analysis and Evaluation of Measurement Techniques for Curing Poly(Methyl Methacrylate) Bone Cement in Vertebroplasty.

Vertebroplasty is a minimally invasive surgical procedure used to treat vertebral fractures, which conventionally involves injecting poly(methyl methacrylate) (PMMA) bone cement into the fractured vertebra. A common risk associated with vertebroplasty is cement leaking out of the vertebra during the injection, which may occur due to a lack of understanding of the complex flow behavior. Therefore, experiments to quantify the cement's flow properties are necessary for understanding and proper handling of the bone cement.

Engineering complex tissue-like microenvironments with biomaterials and biofabrication.

Advances in tissue engineering for both system modeling and organ regeneration depend on embracing and recapitulating the target tissue's functional and structural complexity. Microenvironmental features such as anisotropy, heterogeneity, and other biochemical and mechanical spatiotemporal cues are essential in regulating tissue development and function. Novel biofabrication strategies and innovative biomaterial design have emerged as promising tools to better reproduce such features.

Optimizing the physical properties of collagen/hyaluronan hydrogels by inhibition of polyionic complexes formation at pH close to the collagen isoelectric point.

Collagen/hyaluronan hydrogels with physical properties well suited for biomedical applications are challenging to synthesize due to the formation of polyionic complexes (PICs). A systematic physicochemical study was thus performed to determine novel conditions to inhibit the formation of collagen/hyaluronan PICs and obtain composite hydrogels with high physical properties. Using a range of pH from 1 to 5.

Combining biomimetic collagen/hyaluronan hydrogels with discogenic growth factors promotes mesenchymal stroma cell differentiation into Nucleus Pulposus like cells.

Based on stem cell injection into degenerated Nucleus Pulposus (NP), novel treatments for intervertebral disc (IVD) regeneration were disappointing because of cell leakage or inappropriate cell differentiation. In this study, we hypothesized that mesenchymal stromal cells encapsulated within injectable hydrogels possessing adequate physico-chemical properties would differentiate into NP like cells. Composite hydrogels consisting of type I collagen and tyramine-substituted hyaluronic acid (THA) were prepared to mimic the NP physico-chemical properties.

Alginate microbeads and hydrogels delivering meropenem and bacteriophages to treat Pseudomonas aeruginosa fracture-related infections.

Bacteriophage (phage) therapy has shown promise in treating fracture-related infection (FRI); however, questions remain regarding phage efficacy against biofilms, phage-antibiotic interaction, administration routes and dosing, and the development of phage resistance. The goal of this study was to develop a dual antibiotic-phage delivery system containing hydrogel and alginate microbeads loaded with a phage cocktail plus meropenem and evaluate efficacy against muti-drug resistant Pseudomonas aeruginosa. Two phages (FJK.

Bioactive and chemically defined hydrogels with tunable stiffness guide cerebral organoid formation and modulate multi-omics plasticity in cerebral organoids.

Organoids are an emerging technology with great potential in human disease modelling, drug development, diagnosis, tissue engineering, and regenerative medicine. Organoids as 3D-tissue culture systems have gained special attention in the past decades due to their ability to faithfully recapitulate the complexity of organ-specific tissues. Despite considerable successes in culturing physiologically relevant organoids, their real-life applications are currently limited by challenges such as scarcity of an appropriate biomimetic matrix.

Development of a hyaluronic acid-collagen bioink for shear-induced fibers and cells alignment.

Human tissues are characterized by complex composition and cellular and extracellular matrix (ECM) organization at microscopic level. In most of human tissues, cells and ECM show an anisotropic arrangement, which confers them specific properties., the ability to closely mimic this complexity is limited.

Modulating design parameters to drive cell invasion into hydrogels for osteochondral tissue formation.

Background: The use of acellular hydrogels to repair osteochondral defects requires cells to first invade the biomaterial and then to deposit extracellular matrix for tissue regeneration. Due to the diverse physicochemical properties of engineered hydrogels, the specific properties that allow or even improve the behaviour of cells are not yet clear. The aim of this study was to investigate the influence of various physicochemical properties of hydrogels on cell migration and related tissue formation using , and models.

3D Printing of Extracellular Matrix-Based Multicomponent, All-Natural, Highly Elastic, and Functional Materials toward Vascular Tissue Engineering.

3D printing offers an exciting opportunity to fabricate biological constructs with specific geometries, clinically relevant sizes, and functions for biomedical applications. However, successful application of 3D printing is limited by the narrow range of printable and bio-instructive materials. Multicomponent hydrogel bioinks present unique opportunities to create bio-instructive materials able to display high structural fidelity and fulfill the mechanical and functional requirements for in situ tissue engineering.

Fabrication of Collagen-Hyaluronic Acid Cryogels by Directional Freezing Mimicking Cartilage Arcade-like Structure.

The internal architecture of tissue-like constructs is fundamental to their structural and biological functions. Here, we introduce a simple and robust method to fabricate cryogels based on derivatized extracellular matrix (ECM) macromolecules with porosity arranged according to the typical Benninghoff zonal architecture of articular cartilage. To obtain this arcade-like structure, the technique used the growth of ice crystals from copper pins at cryogenic temperatures.

Swelling-Dependent Shape-Based Transformation of a Human Mesenchymal Stromal Cells-Laden 4D Bioprinted Construct for Cartilage Tissue Engineering.

3D bioprinting is usually implemented on flat surfaces, posing serious limitations in the fabrication of multilayered curved constructs. 4D bioprinting, combining 3D bioprinting with time-dependent stimuli-induced transformation, enables the fabrication of shape-changing constructs. Here, a 4D biofabrication method is reported for cartilage engineering based on the differential swelling of a smart multi-material system made from two hydrogel-based materials: hyaluronan and alginate.

Tuning the Cell-Adhesive Properties of Two-Component Hybrid Hydrogels to Modulate Cancer Cell Behavior, Metastasis, and Death Pathways.

This work presents a polysaccharide and protein-based two-component hybrid hydrogel integrating the cell-adhesive gelatin-tyramine (G-Tyr) and nonadhesive hyaluronic acid-tyramine (HA-Tyr) through enzyme-mediated oxidative coupling reaction. The resulting HA-Tyr/G-Tyr hydrogel reflects the precise chemical and mechanical features of the cancer extracellular matrix and is able to tune cancer cell adhesion upon switching the component ratio. The cells form quasi-spheroids on HA-Tyr rich hydrogels, while they tend to form an invasive monolayer culture on G-Tyr rich hydrogels.

3D printing of inorganic-biopolymer composites for bone regeneration.

In most cases, bone injuries heal without complications, however, there is an increasing number of instances where bone healing needs major clinical intervention. Available treatment options have severe drawbacks, such as donor site morbidity and limited availability for autografting. Bone graft substitutes containing growth factors would be a viable alternative, however they have been associated with dose-related safety concerns and lack control over spatial architecture to anatomically match bone defect sites.