Influence of Bone-Borne Trans-Sutural Distraction Osteogenesis Therapy on the Hard Palate of Growing Children With Cleft Lip and Palate.

ABSTRACT: The efficacy of trans-sutural distraction osteogenesis therapy (TSDO) in treating midfacial hypoplasia in children with cleft lip and palate has been confirmed. However, few studies have reported that changes occur in the palate after TSDO treatment. To study the effect of TSDO on palatal morphology and its relative position in the craniofacial region, we retrospectively collected and measured the computed tomography images of 29 growing children with cleft lip and palate and midfacial hypoplasia, before and after TSDO. The results showed that the length and height of the palate did not change significantly, but the width and arch length increased, and the anterior area was more pronounced than the posterior area, with the median palatine suture still centered without obvious deviation. This suggests lateral palate growth after distraction, most likely around the median palatine suture. The distance from the palate to the cranial base also increased after distraction, and the anterior nasal spine moved forward, whereas the palate rotated by an average of 10.04° downward from the center of the anterior nasal spine. The increasing distance between the palate and cranial base may result from the growth of the nasal bone or the skull base. The oropharyngeal airway volume was also increased by an average of 2256.36 mm3, which may be beneficial to children's ventilatory function. In conclusion, TSDO therapy has influence on patients' palatal morphology and position, which should be considered before surgery.

Porous Core/Dense Shell PLA Microspheres Embedded with High Drug Loading of Bupivacaine Crystals for Injectable Prolonged Release.

Objective of the study was to design an injectable microsphere preparation with high drug loading of bupivacaine for prolonged release and local anesthetic. PLA or PLGA was used as the biodegradable matrix material to fabricate microspheres with the o/w emulsification-solvent evaporation method. The characterization of bupivacaine microspheres was observed by SEM, DSC, and XRPD. The microsphere preparation and extended drug release, as well as the plasma drug concentration and sciatic nerve blockade after injection of the microsphere formulation to rats were investigated. High drug-loading microspheres of more than 70% were successfully obtained with extended drug release over 5 days in vitro depending on the type of matrix and the feed ratio of drug to polymer. SEM, DSC, and XRPD results verified a novel microsphere structure characterized as the porous core composed of PLA material and form II bupivacaine crystals and dense shell formed of PLA layer. The mechanism that bupivacaine was dissolved inside the microsphere and diffused across the dense shell was suggested for drug release in vitro. The optimized PLA microsphere formulation showed low and steady plasma drug concentration over 5 days and prolonged duration of sensory and motor blockade of sciatic nerve lasted more than 3 days. Results indicated that the porous core-shell structure of PLA microsphere formulation would provide enormous potential as an injectable depot for locally prolonged delivery of bupivacaine and control of postoperative pain.

Development of a tannic acid- and silicate ion-functionalized PVA-starch composite hydrogel for in situ skeletal muscle repairing.

The repair capacity of skeletal muscle is severely diminished in massive skeletal muscle injuries accompanied by inflammation, resulting in muscle function loss and scar tissue formation. In the current work, we developed a tannic acid (TA)- and silicate ion-functionalized tissue adhesive poly(vinyl alcohol) (PVA)-starch composite hydrogel, referred to as PSTS (PVA-starch-TA-SiO32-). It was formed based on the hydrogen bonding of TA to organic polymers, as well as silicate-TA ligand interaction. PSTS could be gelatinized in minutes at room temperature with crosslinked network formation, making it applicable for injection. Further investigations revealed that PSTS had skeletal muscle-comparable conductivity and modulus to act as a temporary platform for muscle repairing. Moreover, PSTS could release TA and silicate ions in situ to inhibit bacterial growth, induce vascularization, and reduce oxidation, paving the way to the possibility of creating a favorable microenvironment for skeletal muscle regeneration and tissue fibrosis control. The in vivo model confirmed that PSTS could enhance muscle fiber regeneration and myotube formation, as well as reduce infection and inflammation risk. These findings thereby implied the great potential of PSTS in the treatment of formidable skeletal muscle injuries.

Pregelatinized hydroxypropyl distarch phosphate-reinforced calcium sulfate bone cement for bleeding bone treatment.

Considering the shortcomings of known medical hemostatic materials such as bone wax for bleeding bone management, it is essential to develop alternative bone materials capable of efficient hemostasis and bone regeneration and adaptable to clinical surgical needs. Thus, in the current work, a calcium sulfate hemihydrate and starch-based composite paste was developed and optimized. Firstly, it was found that the use of hydroxypropyl distarch phosphate (HDP) coupled with pregelatinization could generate an injectable, malleable and self-hardening paste with impressive anti-collapse ability in a dynamic aqueous environment, suggesting its potential applicability in both open and minimally invasive clinical practice. The as-hardened matrix exhibited a compressive strength of up to 61.68 ± 5.13 MPa compared to calcium sulfate cement with a compressive strength of 15.16 ± 2.42 MPa, making it a promising candidate for the temporary mechanical stabilization of bone defects. Secondly, the as-prepared paste revealed superior hemostasis and bone regenerative capabilities compared to calcium sulfate cement and bone wax, with greatly enhanced bleeding management and bone healing outcomes when subjected to testing in in vitro and in vivo models. In summary, our results confirmed that calcium sulfate bone cement reinforced with the selected starch can act as a reliable platform for bleeding bone treatment, overcoming the limitations of traditional bone hemostatic agents.

Fabrication of a Nanoscale Magnesium/Copper Metal-Organic Framework on Zn-Based Guided Bone Generation Membranes for Enhancing Osteogenesis, Angiogenesis, and Bacteriostasis Properties.

Recently, zinc (Zn) and its alloys have demonstrated great potential as guided bone regeneration (GBR) membranes to treat the problems of insufficient alveolar bone volume and long-term osseointegration instability during dental implantology. However, bone regeneration is a complex process consisting of osteogenesis, angiogenesis, and antibacterial function. For now, the in vivo osteogenic performance and antibacterial activity of pure Zn are inadequate, and thus fabricating a platform to endow Zn membranes with multifunctions may be essential to address these issues. In this study, various bimetallic magnesium/copper metal-organic framework (Mg/Cu-MOF) coatings were fabricated and immobilized on pure Zn. The results indicated that the degradation rate and water stability of Mg/Cu-MOF coatings could be regulated by controlling the feeding ratio of Cu2+. As the coating and Zn substrate degraded, an alkaline microenvironment enriched with Zn2+, Mg2+, and Cu2+ was generated. It significantly improved calcium phosphate deposition, differentiation of osteoblasts, and vascularization of endothelial cells in the extracts. Among them, Mg/Cu1 showed the best comprehensive performance. The superior antibacterial activity of Mg/Cu1 was demonstrated in vitro and in vivo, which indicated significantly enhanced bacteriostatic activity against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli as compared to that of the bare sample. Bimetallic Mg/Cu-MOF coating could properly coordinate the multifunction on a Zn membrane and could be a promising platform for promoting its bone regeneration, which could pave the way for Zn-based materials to be used as barrier membranes in oral clinical trials.

Incorporation of Magnesium and Zinc Metallic Particles in PLGA Bi-layered Membranes with Sequential Ion Release for Guided Bone Regeneration.

Guided bone regeneration (GBR) membranes are commonly used for periodontal tissue regeneration. Due to the complications of existing GBR membranes, the design of bioactive membranes is still relevant. GBR membranes with an asymmetric structure can accommodate the functional requirements of different interfacial tissues. Here, poly(lactic acid-glycolic acid) (PLGA) was selected as the matrix for preparing a bi-layered membrane with both dense and porous structure. The dense layer for blocking soft tissues was incorporated with zinc (Zn) particles, while the porous layer for promoting bone regeneration was co-incorporated with magnesium (Mg) and Zn particles. Mg/Zn-embedded PLGA membranes exhibited 166% higher mechanical strength in comparison with pure PLGA membranes and showed suitable degradation properties with a sequential ion release behavior of Mg2+ first and continuously Zn2+. More importantly, the release of Zn2+ from bi-layered PLGA endowed GBR membranes with excellent antibacterial activity (antibacterial rate > 69.3%) as well as good cytocompatibility with MC3T3-E1 (mouse calvaria pre-osteoblastic cells) and HGF-1 (human gingival fibroblast cells). Thus, the asymmetric bi-layered PLGA membranes embedded with Mg and Zn particles provide a simple and effective strategy to not only reinforce the PLGA membrane but also endow membranes with osteogenic and antibacterial activity due to the continuous ion release profile, which serves as a promising candidate for use in GBR therapy.

Development of polydopamine functionalized porous starch for bleeding control with the assistance of NIR light.

Efficient hemorrhage control of severe wound injuries is an urgent medical need, deserving agents with promising blood coagulation and biocompatible characteristics. Current work developed polydopamine (PDA) functionalized porous starch powder (PS-PDA) for emergency bleeding treatment. The micro-morphology and elements, chemical groups, and porosity of PS-PDA were systematically characterized. Its comparison with porous starch (PS) revealed the promising potential of this composite in medical practice. On one hand, PS-PDA showed superior surface area and biomineralization affinity over PS, along with comparable hemo/cyto-compatibility. On the other hand, the photothermal effect of PDA under near Infrared (NIR) light paved the possibility to accelerate blood coagulation in situ. In vivo studies indicated PS-PDA can significantly reduce blood loss and improvement of hemostasis efficiency accompanied by NIR light exposure. These results suggest that this newly developed PS-PDA powder can serve as a promising hemostatic material for bleeding wound control.

Polydopamine functionalized porous starch (PS-PDA) was developed for bleeding controlPS-PDA showed superior surface area and biomineralization affinity over PSWith assistance of NIR irradiation, PS-PDA can accelerate blood coagulationPS-PDA showed therapeutic potential for both soft and hard tissue bleeding wound.

Animal Models of Femur Head Necrosis for Tissue Engineering and Biomaterials Research.

Femur head necrosis, also known as osteonecrosis of the femoral head (ONFH), is a widespread disabling pathology mostly affecting young and middle-aged population and one of the major causes of total hip arthroplasty in the elderly. Currently, there are limited number of different clinical or medication options for the treatment or the reversal of progressive ONFH, but their clinical outcomes are neither satisfactory nor consistent. In pursuit of more reliable therapeutic strategies for ONFH, including recently emerged tissue engineering and biomaterials approaches, in vivo animal models are extremely important for therapeutic efficacy evaluation and mechanistic exploration. Based on the better understanding of pathogenesis of ONFH, animal modeling method has evolved into three major routes, including steroid-, alcohol-, and injury/trauma-induced osteonecrosis, respectively. There is no consensus yet on a standardized ONFH animal model for tissue engineering and biomaterial research; therefore, appropriate animal modeling method should be carefully selected depending on research purposes and scientific hypotheses. In this work, mainstream types of ONFH animal model and their modeling techniques are summarized, showing both merits and demerits for each. In addition, current studies and experimental techniques of evaluating therapeutic efficacy on the treatment of ONFH using animal models are also summarized, along with discussions on future directions related to tissue engineering and biomaterial research. Impact statement Exploration of tissue engineering and biomaterial-based therapeutic strategy for the treatment of femur head necrosis is important since there are limited options available with satisfactory clinical outcomes. To promote the translation of these technologies from benchwork to bedside, animal model should be carefully selected to provide reliable results and clinical outcome prediction. Therefore, osteonecrosis of the femoral head animal modeling methods as well as associated tissue engineering and biomaterial research are overviewed and discussed in this work, as an attempt to provide guidance for model selection and optimization in tissue engineering and biomaterial translational studies.

A multi-functional SiO32--releasing hydrogel with bioinspired mechanical properties and biodegradability for vascularized skeletal muscle regeneration.

Vascularized skeletal muscle regeneration remains a great medical need but significant challenge. Biomaterial strategies that can facilitate the regeneration of muscle fibers and blood vessels are unavailable. Herein, we report a new cell- and drug-free biomaterial-based strategy for the repair of severely injured skeletal muscles. A novel multi-functional silicate ion-releasing hydrogel (SRH) was developed by dissolving PVA and starch in Na2SiO3 solutions, followed by freeze-thawing treatment. The mechanical properties and degradation profile of the SRH could be easily adjusted by altering the amylose/amylopectin ratio of starch. The SRH efficiently releases silicate ions to create a favorable microenvironment for enhanced skeletal muscle repair, while the mechanical properties and biodegradability of SRHs is adjusted to match the muscle regeneration environment. Silicate ions released from the SRH simultaneously promote myoblast proliferation and myogenic differentiation, decrease oxidative stress, and enhance the angiogenesis of vascular endothelial cells in vitro. Silicate ions released from the SRH scaffold with bioinspired mechanical properties and biodegradability promote the de novo formation of muscle fibers and blood vessels while inhibiting tissue fibrosis, leading to enhanced vascularized muscle regeneration in vivo. With multiple biofunctions and mechanical/degradation tunability, the SRH platform bears great potential in the skeletal muscle tissue engineering and treatment of formidable clinical problems such as volumetric muscle loss and sarcopenia.

Strontium-calcium phosphate hybrid cement with enhanced osteogenic and angiogenic properties for vascularised bone regeneration.

Vascularized bone tissue engineering is regarded as one of the optimal treatment options for large bone defects. The lack of angiogenic properties and unsatisfactory physicochemical performance restricts calcium phosphate cement (CPC) from application in vascularized bone tissue engineering. Our previous studies have developed a starch and BaSO4 incorporated calcium phosphate hybrid cement (CPHC) with improved mechanical strength and handling properties. However, the bioactivity-especially the angiogenic ability-is still absent and requires further improvement. Herein, based on the reported CPHC and the osteogenic and angiogenic properties of strontium (Sr) ions, a strontium-enhanced calcium phosphate hybrid cement (Sr-CPHC) was developed to improve both biological and physicochemical properties of CPC. Compared to CPC, the initial setting time of Sr-CPHC was prolonged from 2.2 min to 20.7 min. The compressive strength of Sr-CPHC improved from 11.21 MPa to 45.52 MPa compared with CPC as well. Sr-CPHC was biocompatible and showed promotion of alkaline phosphatase (ALP) activity, calcium nodule formation and osteogenic relative gene expression, suggesting high osteogenic-inductivity. Sr-CPHC also facilitated the migration and tube formation of human umbilical vein endothelial cells (HUVECs) in vitro and up-regulated the expression of the vascular endothelial growth factor (VEGF) and Angiopoietin-1 (Ang-1). In vivo evaluation showed marked new bone formation in a rat calvarial defect model with Sr-CPHC implanted. Sr-CPHC also exhibited enhancement of neovascularization in subcutaneous connective tissue in a rat subcutaneous implantation model. Thus, the Sr-CPHC with the dual effects of osteogenesis and angiogenesis shows great potential for clinical applications such as the repair of ischemic osteonecrosis and critical-size bone defects.

Ultra-Conformable Ionic Skin with Multi-Modal Sensing, Broad-Spectrum Antimicrobial and Regenerative Capabilities for Smart and Expedited Wound Care.

While rapid wound healing is essential yet challenging, there is also an unmet need for functional restoration of sensation. Inspired by natural skin, an ultra-conformable, adhesive multi-functional ionic skin (MiS) with multi-modal sensing capability is devised for smart and expedited wound care. The base of MiS is a unique skin-like, conductive and self-adaptive adhesive polyacrylamide/starch double-network hydrogel (PSH) and self-powered, flexible, triboelectric sensor(s) is integrated on top of PSH for multi-tactile sensing. MiS could enhance wound contraction, collagen deposition, angiogenesis, and epidermis formation in a full-thickness skin defect wound model in vivo, while significantly inhibiting the biofilm formation of a wide range of microorganisms. MiS also exhibits multi-modal sensing capability for smart and instant therapeutics and diagnostics, including skin displacement or joint motion, temperature, pressure and tissue exudate changes of wound bed, and locally releasing drugs in a pH-responsive manner. More importantly, MiS could restore the skin-mimicking tactile sensing function of both touch location and intensity, and thus could be used as a human-machine interface for accurate external robotic control. MiS demonstrates a new comprehensive paradigm of combining wound diagnosis and healing, broad-spectrum anti-microbial capability and restoration of multi-tactile sensing for the reparation of severe wound.

Calcium phosphate-based composite cement: Impact of starch type and starch pregelatinization on its physicochemical properties and performance in the vertebral fracture surgical models in vitro.

Calcium phosphate cement (CPC) modified with native and pregelatinized normal corn and waxy maize starches was studied. Effects of starch pregelatinization and starch type on the physicochemical properties of CPC were investigated. CPC modified with pregelatinized normal corn starch (CPB-PNC) or pregelatinized waxy maize starch (CPB-PW) was evaluated by two vertebral fracture surgical models in vitro. Both granular and pregelatinized starches significantly improved the setting times and injectability of CPC, but only the pregelatinized starches improved the anti-collapsibility and compressive strength of CPC significantly. CPB-PW, whose micro-structure was compact and uniform, showed the best physicochemical properties. Addition of starch did not inhibit the hydro-reaction of CPC. Unmodified CPC had very poor dispersibility and could not apply in the tests of the surgical models. Pregelatinized starch especially waxy maize starch improved the dispersibility of CPC and showed good dispersion area, volume, improved pull-out force and maximum torque in the Sawbones sponge model. Similarly, in the minimally invasive kyphoplasty model, CPB-PNC and CPB-PW could disperse in the osteoporotic sheep vertebrae and improve the compressive strength of the sheep vertebral body. In conclusion, starch pregelatinization and starch botanical source affect the physicochemical properties of CPC significantly. Bone cements modified by different starches also performed differently in surgical models for osteoporotic vertebral fracture. Pregelatinized waxy maize starch may be a better candidate for CPC modification comparing to the pregelatinized normal corn starch.

An effective dual-factor modified 3D-printed PCL scaffold for bone defect repair.

Numerous bioactive molecules produced in cells are involved in the process of bone formation. We consider that appropriate, simultaneous application of two types of bioactive molecules would accelerate the regeneration of tissues and organs. Therefore, we combined aspirin-loaded liposomes (Asp@Lipo) and bone forming peptide-1 (BFP-1) on three dimensional-printed polycaprolactone (PCL) scaffold and determined whether this system improved bone regeneration outcomes. in vitro experiments indicated that Asp@Lipo/BFP-1at a 3:7 ratio was the best option for enhancing the osteogenic efficiency of human mesenchymal stem cells (hMSCs). This was confirmed in an in vivo cranial defect animal model. In addition, RNA-Seq was applied for preliminarily exploration of the mechanism of action of this composite scaffold system, and the results suggested that it mainly improved bone regeneration via the PI3K/AKT signaling pathway. This approach will have potential for application in bone tissue engineering and regenerative medicine.

Enhancing effects of radiopaque agent BaSO4 on mechanical and biocompatibility properties of injectable calcium phosphate composite cement.

Kyphoplasty is an effective minimally invasive surgical treatment of osteoporotic vertebral compression fractures. Current problems associated with kyphoplasty require better injectable bone cements with improved biodegradability and osseointegrative property as an alternative to polymethyl methacrylate (PMMA) bone cement. Calcium phosphate cements (CPCs) possess superior biodegradability and osteoconductivity but inferior injectability and mechanical strengths, rendering them unsuitable for kyphoplasty applications. Our previous studies developed a corn starch-reinforced CPC with improved handling, injectable and mechanical properties, yet for kyphoplasty applications the reinforced CPC needs to have radiopacity and further enhanced mechanical strength. This work therefore developed a CPC-Starch-BaSO4 (CSB) system and investigated the effects of radiopaque agent BaSO4 on injectability, radiopacity, mechanical and biocompatibility properties of the system. Results showed that the addition of BaSO4 significantly improved radiopacity and mechanical strengths of CPC cement. In addition, in vitro evaluations including apoptosis, hemolysis and endotoxin tests and in vivo evaluation of subcutaneous implantation all revealed that CSB was biocompatible. This study demonstrates that CSB could meet the clinical requirements for minimally invasive surgery and thus have great potential for kyphoplasty applications.

Effect of surgical factors on the augmentation of cement-injectable cannulated pedicle screw fixation by a novel calcium phosphate-based nanocomposite.

Bone cement-augmented pedicle screw system demonstrates great efficacy in spinal disease treatments. However, the intrinsic drawbacks associated with clinically used polymethylmethacrylate (PMMA) cement demands for new bone cement formulations. On the basis of our previous studies, a novel injectable and biodegradable calcium phosphate-based nanocomposite (CPN) for the augmentation of pedicle screw fixation was systematically evaluated for its surgical feasibility and biomechanical performance by simulated and animal osteoporotic bone models, and the results were compared with those of clinical PMMA cement. ASTM-standard solid foam and open-cell foam models and decalcified sheep vertebra models were employed to evaluate the augmentation effects of CPN on bone tissue and on the cement-injected cannulated pedicle screws (CICPs) placed in osteoporotic bone. Surgical factors in CICPs application, such as injection force, tapping technique, screw diameter, and pedicle screw loosening scenarios, were studied in comparison with those in PMMA. When directly injected to the solid foam model, CPN revealed an identical augmentation effect to that of PMMA, as shown by the similar compressive strengths (0.73 ± 0.04 MPa for CPN group vs. 0.79 ± 0.02 MPa for PMMA group). The average injection force of CPN at approximately 40-50 N was higher than that of PMMA at approximately 20 N. Although both values are acceptable to surgeons, CPN revealed a more consistent injection force pattern than did PMMA. The dispersing and anti-pullout ability of CPN were not affected by the surgical factors of tapping technique and screw diameter. The axial pullout strength of CPN evaluated by the decalcified sheep vertebra model revealed a similar augmentation level as that of PMMA (1351.6 ± 324.2 N for CPN vs. 1459.7 ± 304.4 N for PMMA). The promising results of CPN clearly suggest its potential for replacing PMMA in CICPs augmentation application and the benefits of further study and development for clinical uses.

A hybrid 3D-printed aspirin-laden liposome composite scaffold for bone tissue engineering.

Bone defects are some of the most difficult injuries to treat in clinical medicine. Evidence from cellular and animal studies suggests that aspirin exhibits protective effects on bone by promoting both the survival of osteoblast precursor stem cells and osteoblast differentiation. However, acquired resistance to aspirin and its cytotoxicity significantly limit its therapeutic application. Controlled release systems have been confirmed to promote the efficacy of certain drugs for bone regeneration. Additionally, the controlled release of a high dose of drug allows for lower dosing over an extended period. In this way, nano-liposomal encapsulation of aspirin can be used to reduce the cytotoxicity of the overall dose. Using a series of osteogenic experiments, this study found that an aspirin-laden liposome delivery system (Asp@Lipo) obviously promoted osteogenesis and immunomodulation of human mesenchymal stem cells (hMSCs). We also studied the in vitro capacity of polycaprolactone (PCL)-based bioactive composite (PCL-Asp@Lipo) scaffolds to facilitate cell proliferation and osteoblast differentiation. Compared to a common scaffold, ALP assays, immunofluorescence and calcium mineralisation studies revealed that the PCL-Asp@Lipo scaffolds enhanced the osteogenic differentiation of hMSCs. Subsequently, along with the cells, PCL and PCL-Asp@Lipo scaffolds were both implanted subcutaneously into nude mice for estimation of osteo-inductivity after 6 weeks, the PCL-Asp@Lipo composite scaffold exhibited more osteogenic activity than the bare PCL scaffold. This approach has potential applications in bone tissue repair and regenerative medicine.

A viscoelastic adhesive epicardial patch for treating myocardial infarction.

Acellular epicardial patches that treat myocardial infarction by increasing the mechanical integrity of damaged left ventricular tissues exhibit widely scattered therapeutic efficacy. Here, we introduce a viscoelastic adhesive patch, made of an ionically crosslinked transparent hydrogel, that accommodates the cyclic deformation of the myocardium and outperforms most existing acellular epicardial patches in reversing left ventricular remodelling and restoring heart function after both acute and subacute myocardial infarction in rats. The superior performance of the patch results from its relatively low dynamic modulus, designed at the so-called 'gel point' via finite-element simulations of left ventricular remodelling so as to balance the fluid and solid properties of the material.

A versatile three-dimensional foam fabrication strategy for soft and hard tissue engineering.

The fabrication strategies of three-dimensional porous biomaterials have been extensively studied and well established in the past few decades, yet the biocompatibility and versatility of porous architecture preparation is still lacking. Herewith, we present a novel and green 3D porous foam fabrication technique for both soft and hard engineering. By utilizing the gelatinization and retrogradation properties of starches, stabilized porous constructs made of various building blocks, from living cells to ceramic particles, were created for the first time. In soft tissue engineering applications, 3D cultured tissue foam (CTF) with controlled cell release properties was developed, and foams constituting osteoblasts, fibroblasts and vascular endothelial cells all exhibited high mechanical stability and preservation of cell viability or functions. More importantly, the CTF achieved sustained self-release of cells controlled by serum concentration (containing amylase) and the released cells also maintained high viability and functions. In the context of hard tissue engineering applications, ceramic/bioglass (BG) foam scaffolds were developed by a similar starch-assisted foaming strategy where the resultant bone scaffolds of hydroxyapatite (HA)/BG and Si3N4/BG possessed >70% porosity with interconnected macropores (sizes 200 âˆ¼ 400 µm), fine pores (sizes 1 âˆ¼ 10 µm) and superior mechanical properties despite the high porosity. Additionally, in vitro and in vivo evaluations of the biological properties revealed that porous HA/BG foam exhibits the desired biocompatibility and osteogenesis. The in vivo study indicated new bone ingrowth after 1 week and significant increases in new bone volume after 2 weeks. In conclusion, the presented foaming strategy provides opportunities for biofabricating CTF with different cells for different target soft tissues and preparing porous ceramic/BG foams with different material components and high strengths, showing great versatility in soft and hard tissue engineering.

Nanotechnology-enabled materials for hemostatic and anti-infection treatments in orthopedic surgery.

The hemostatic and anti-infection treatments in the field of orthopedics are always the pivotal yet challenging topics. In the first part of this review, synthesized or naturally derived nanoscale agents and materials for hemostatic treatment in orthopedic surgery are introduced. The hemostatic mechanisms and the safety concerns of these nanotechnology-enabled materials are discussed. Beside the materials to meet hemostatic needs in orthopedic surgery, the need for antimicrobial or anti-infection strategy in orthopedic surgery also becomes urgent. Nanosilver and its derivatives have the most consistent anti-infective effect and thus high translational potential for clinical applications. In the second part, the factors affecting the antimicrobial effect of nanosilver and its application status are summarized. Finally, the status and translational potential of various nanotechnology-enabled materials and agents for hemostatic and anti-infective treatments in orthopedic surgery are discussed.

A novel injectable calcium phosphate-based nanocomposite for the augmentation of cannulated pedicle-screw fixation.

Polymethyl methacrylate (PMMA)-augmented cannulated pedicle-screw fixation has been routinely performed for the surgical treatment of lumbar degenerative diseases. Despite its satisfactory clinical outcomes and prevalence, problems and complications associated with high-strength, stiff, and nondegradable PMMA have largely hindered the long-term efficacy and safety of pedicle-screw fixation in osteoporotic patients. To meet the unmet need for better bone cement for cannulated pedicle-screw fixation, a new injectable and biodegradable nanocomposite that was the first of its kind was designed and developed in the present study. The calcium phosphate-based nanocomposite (CPN) exhibited better anti-pullout ability and similar fluidity and dispersing ability compared to clinically used PMMA, and outperformed conventional calcium phosphate cement (CPC) in all types of mechanical properties, injectability, and biodegradability. In term of axial pullout strength, the CPN-augmented cannulated screw reached the highest force of ~120 N, which was higher than that of PMMA (~100 N) and CPC (~95 N). The compressive strength of the CPN (50 MPa) was three times that of CPC, and the injectability of the CPN reached 95%. In vivo tests on rat femur revealed explicit biodegradation of the CPN and subsequent bone ingrowth after 8 weeks. The promising results for the CPN clearly suggest its potential for replacing PMMA in the application of cannulated pedicle-screw fixation and its worth of further study and development for clinical uses.