In the present study we developed an injectable, bioactive and degradable hydrogel composed of alginate at 2.5% oxidation degree and calcium-activated platelet rich plasma (PRP) for wound healing applications (PRP-HG-2.5%). The alginate gives mechanical support to the hydrogel while the activated PRP provides growth factors that enhance wound healing and fibrin which creates an adequate microenvironment for cell migration and proliferation. The rheological and mechanical properties of the hydrogel were characterized. Further characterization revealed that PRP-HG-2.5% showed a faster hydrolitic degradation rate than unmodified alginate and a similar platelet derived growth factor (PDGF-BB) release profile. In vitro efficacy studies, carried out in human fibroblasts and keratinocytes, showed that PRP-HG-2.5% was not cytotoxic and that it was able to promote cell adhesion and proliferation. Thereafter, in an in vivo full thickness wound healing study conducted in diabetic mice, no differences were found among PRP-HG-2.5% and its counterpart without PRP, likely due to the xenogeneic origin of the PRP. This hypothesis was validated in vitro, since a cytotoxic effect was observed after human PRP application to mouse fibroblasts. Therefore, PRP-HG-2.5% might be a promising strategy for chronic woundstreatment, although its effectiveness should be evaluated in a more reliable preclinical model.

Scaffolds combined with bioactive agents can enhance bone regeneration at therapeutic sites. We explore whether combined supplementation with coumaric acid and recombinant human-cartilage oligomeric matrix protein-angiopoietin 1 (rhCOMP-Ang1) is an ideal approach for bone tissue engineering. We developed coumaric acid-conjugated absorbable collagen scaffold (CA-ACS) and investigated whether implanting CA-ACS in combination with rhCOMP-Ang1 facilitates ACS- or CA-ACS-mediated bone formation using a rat model of critically sized mandible defects. We examined the mechanisms by which coumaric acid and rhCOMP-Ang1 regulate behaviors of human periodontal ligament fibroblasts (hPLFs). The CA-ACS exhibits greater anti-degradation and mechanical strength properties than does ACS alone. Implanting CA-ACS loaded with rhCOMP-Ang1 greatly enhances bone regeneration at the defect via the activation of angiogenic, osteogenic, and anti-osteoclastic responses compared with other rat groups implanted with an ACS alone or CA-ACS. Treatment with both rhCOMP-Ang1 and coumaric acid increases proliferation, mineralization, and migration of cultured hPLFs via activation of the Ang1/Tie2 signaling axis at a greater rate than treatment with either of them alone. Collectively, this study demonstrates that CA-ACS impregnated with rhCOMP-Ang1 enhances bone regeneration at therapeutic sites, and this enhancement is associated with a synergistic interaction between rhCOMP-Ang1-mediated angiogenesis and coumaric acid-related antioxidant responses.

Biotin is one of the water-soluble B-complex group of vitamins. Recent studies have found that the relative protein expression of BMP2, BSP and OPG in MC3T3-E1 cells is prominent after 14 days of co-culture with biotin film, especially for BMP2. It is also found that the rapid degradation of biotin film in vivo limits its application value. In this work, magnesium-doped hydroxyapatite (MgHA) film can form a porous network structure as a biological sustained-release film. Therefore, the multilayer (MgHA|biotin|MgHA|biotin) film was prepared by pulsed laser assisted electron beam deposition technique. The morphology, structure and properties of biotin film and multilayer film were analyzed and characterized. Also, the osteogenic effect of biotin film and multilayer film was evaluated after implantation into the femoral bone marrow cavity of SD rats. The results of micro-CT scan and 3D reconstruction showed that there were a large number of trabecular bones around the multilayer film, which was superior to biotin film in osteogenesis. Hematoxylin-eosin staining showed cancellous bone structure and intact bone marrow structure around the multilayer film, and the newly formed bone became lamellar. Masson-trichromatic staining revealed abundant osteoid and braided bone formation around the multilayer film. In conclusion, MgHA sustained release film can realize the continuous release of bioactive drugs, which provides a new route to accelerate the repair of bone defects.

Herein, a novel microfibrillated cellulose (MFC) reinforced natural polymer-based sponge composed of carboxymethyl chitosan (CMC) and oxidized starch (OS) with hemostatic, repairing-promoting, and antimicrobial performances was fabricated for chronic wound repair. When the content of MFC reached 1.2 wt%, the prepared sponge exhibited ultra-fast water or blood-trigged shape recovery property within 3 s. Moreover, sponge was functionally modified with silver nanoparticles (AgNPs) and recombinant humanized collagen type III (rhCol III). The AgNPs and rhCol III loaded sponge (A-Ag/III) could effectively kill a broad spectrum of pathogenic microbes, promote the proliferation and migration of L929 cells in vitro. Due to their erythrocyte-aggregating ability and positive-charge feature of CMC, the A-Ag/III displayed rapid hemostasis ability. Furthermore, the in vivo animal experiment demonstrated the A-Ag/III could promote wound repair by inhibiting inflammation, promoting angiogenesis, and cell proliferation.

Magnetic bioactive glass-ceramics are biomaterials applied for magnetic hyperthermia in bone cancer treatment, thereby treating the bone tumor besides regenerating the damaged bone. However, combining high bioactivity and high saturation magnetization remains a challenge since the thermal treatment step employed to grow magnetic phases is also related to loss of bioactivity. Here, we propose a new nanocomposite made of superparamagnetic iron oxide nanoparticles (SPIONs) dispersed in a sol-gel-derived bioactive glass matrix, which does not need any thermal treatment for crystallization of magnetic phases. The scanning and transmission electron microscopies, X-ray diffraction, and dynamic light scattering results confirm that the SPIONs are actually embedded in a nanosized glass matrix, thus forming a nanocomposite. Magnetic and calorimetric characterizations evidence their proper behavior for hyperthermia applications, besides evidencing inter-magnetic nanoparticle interactions within the nanocomposite. Bioactivity and in vitro characterizations show that such nanocomposites exhibit apatite-forming properties similar to the highly bioactive parent glass, besides being osteoinductive. This methodology is a new alternative to produce magnetic bioactive materials to which the magnetic properties only rely on the quality of the SPIONs used in the synthesis. Thereby, these nanocomposites can be recognized as a new class of bioactive materials for applications in bone cancer treatment by hyperthermia.

Osteomyelitis is commonly developed via hematogenous spreading or direct inoculation of bacteria from orthopedics trauma. Pathogens-induced bone destruction impedes the penetration of antibiotics to the infection site, and the severe inflammation further compromises the traditional treatment outcome. In this work, vancomycin-loaded oligochitosan nanoparticles (Van-NPs) with antibacterial, antibiofilm, antioxidant as well as bone regenerative properties are prepared using sodium tripolyphosphate (TPP) as a crosslinker, and employed for the treatment of osteomyelitis. Van-NPs exhibit strong interactions with dissociative S. aureus and biofilms due to the positive zeta potential, the additional effect between vancomycin (Van) and oligochitosan (OCS) further contributes to an enhanced antibacterial and antibiofilm outcome. The in vitro osteogenic differentiation of rBMSCs is facilitated by the antioxidant ability of Van-NPs and the TPP-induced activation of ERK1/2 and p38 signaling pathways. Moreover, the combination of Van-NPs with PLGA-PEG-PLGA gel (Gel/Van-NPs) achieves successful localized treatment of osteomyelitis in terms of enhanced bacteria elimination, inflammatory modulation, and accelerated bone regeneration. Therefore, Gel/Van-NPs may serve as a promising biomaterial for the optimal treatment of osteomyelitis.

In this study, a novel hybrid bilayer wound dressing (HBD) has been developed for delivering a thermally unstable probiotic, Lactobacillus brevis. The HBD was composed of two layer, a hydrocolloid layer and a Lactobacillus brevis-loaded hydrogel layer as a block supporter and drug carrier, respectively. Moreover, various probiotic-loaded hydrogel layers in HBD were prepared with polyvinyl alcohol (PVA) and numerous hydrophilic polymers via a freezing and thawing method, and their mechanical property, release and wound recovery were assessed. Among the hydrophilic polymers investigated, copovidone most improved the mechanical strength, swelling ability, and release properties; and thus, copovidone/PVA (ratio of 1.0/10) was determined as an appropriate composition of hydrogel layer in HBD. The selected HBD exhibited superior stability than conventional dressing, maintaining approximately 90% of Lactobacillus brevis (9.0 × 10 CFU) during the preparation and storage process. Moreover, the HBD had about 5- and 4-fold better swelling ability and elasticity compared to the conventional dressing. Additionally, it exhibited superior recovery efficacy than the commercial dressing in the animal study. Therefore, this HBD system for delivering a thermally unstable Lactobacillus brevis would be a promising wound dressing with excellent mechanical property and wound recovery.

Glycosaminoglycans (GAGs) are essential for cell-cell and cell-ECM interactions. Unique structures of GAGs provide high affinities to specific cell receptors. Especially, hyaluronic acid (HA), chondroitin sulfate (CS), and heparin are known to have affinities to the liver sinusoidal endothelial cells (LSECs), so they have been utilized as a ligand for liver targeting nanoparticle systems. In this study, we compared different GAGs as a targeted cell delivery ligand by using lipid-conjugated GAGs. Conjugated lipids of GAGs could provide a stable coating over 2 days on the surface of human adipose-derived stem cells (hADSCs) by physical insertion. The hADSCs coated by different GAGs were intravenously injected into mice, and the biodistribution of cells was analyzed by an In Vivo Imaging System (IVIS) to compare the effect of various GAGs on the modulation of biodistribution of stem cells. The results showed that all three GAGs could provide less entrapment in the lung but enhanced accumulation in the liver and spleen. Especially, HA- and heparin coating on hADSCs showed a 1.5-fold higher accumulation than CS-coating on hADSCs in the liver and spleen. Thus, lipid-conjugated HA and heparin are potentially useful coating materials for the liver or spleen-targeted delivery system of therapeutic stem cells.

Tumor cells cultured in a physiologically related three-dimensional (3D) matrix can replicate many basic characteristics of tumor tissue. Tumor tissues are harder than normal, so when using hydrogels for 3D tumor cell culture, attempts have been made to prepare hydrogel scaffolds that mimic the hardness of tumor tissues without reducing the porosity. In this study, a new 3D loofah-inspired scaffold was developed for prostate cancer cell culture. Since the loofah sponge structure of the spacer fabric, the composite scaffolds had a compression modulus similar to that of natural prostate tumor tissue at a lower hydrogel concentration (0.25% W/V), and also, endowed the scaffold with high porosity (85 ± 2.52%) for mass transfer. The results of in vitro cell experiments showed that the composite scaffold can support tumor cells to form clusters in a short time (3 days). Preliminary chemosensitivity analysis showed that the drug resistance of the composite scaffold was significantly higher than that of two-dimensional (2D) culture and COL scaffold. Therefore, the 3D tumor cell culture scaffold with bionic structures has the potential to be used as a tumor drug screening model.

Successful repair and desirable functional recovery of large-gap nerve injuries using artificial nerve implants remains a significant clinical challenge. The beneficial bionic microenvironment within scaffolds can significantly promote the outgrowth of newborn nerve tissues after implantation. Herein, we developed an aligned silk-inspired fiber scaffold (RGD@ASFFs) with a synergistic effect of an extracellular matrix mimicking physical cues and RGD (Arg-Gly-Asp) signals to provide an enhanced cell-friendly microenvironment for repairing large-gap peripheral nerve injuries. The topographic alignment of the methacrylated silk fibroin electrospun fibers effectively facilitated axonal guidance and oriented Schwann cell growth. Importantly, the mechanical cue combined with cell adhesion signals provided by RGD peptides further triggered enriched myelination of Schwann cells by nuclear translocation of Yes-associated protein 1 (YAP) to secrete neurotrophins to support axonal growth. Moreover, benefiting from improved neuronal extension and re-myelination, promising motor function recovery in vivo was achieved by RGD@ASFFs, which is comparable to that of autografts. Thus, the design of this engineered bionic scaffold is a powerful strategy for peripheral nerve defect repair.

Osteoplastic materials PLA/PCL/HA and PHB/HA and scaffolds with a highly porous structure based on them with potential applications in regenerative medicine have been obtained by solvent casting with thermopressing and salt leaching for PLA-based samples and solid-state mixing with subsequent thermopressing and salt leaching for PHB-based samples. The scaffolds were characterized by SEM-EDX, DSC, FTIR spectroscopy, mechanical tests in compression, measurement of the contact angle, in vitro studies, including loading by recombinant BMP-2 and EPO and their release kinetics, and in vivo studies on a model of regeneration of critical-sized cranial defects in mice. Biomimetic scaffolds with micropores sizes ranged from 300 to 500 μm and volume porosity of 70% imitate trabecular bone's structure and have increased hydrophilicity to achieve osteoconductive properties. Mechanical characteristics correspond to native trabecular bone. Elastic modulus - key mechanical characteristics of bone implants - showed the values of 0.15 ± 0.04 and 0.18 ± 0.08 GPa for PLA/PCL/HA and PHB/HA scaffolds, respectively. Both materials have high biocompatibility and can be used together with recombinant proteins BMP-2 and EPO. Introduction of BMP-2 leads to induction of new bone formation, introduction of EPO results in increased angiogenesis in the implantation area. The obtained scaffolds with recombinant proteins can be used as bone implants for reconstruction of defects of lightly or non-loaded bones.

Cell behaviour is influenced by external factors including the physical properties of the substrate such as its surface topography and stiffness. Recent studies have demonstrated the potential of aerogels as biomaterials and specifically as neural scaffolds. The 3-D structure inherent to aerogels offers an advantage over other biocompatible substrates which lack the dimensionality needed to mimic the in vivo topography of tissues. Here, we used a variety of aerogel types to correlate the extension of neurites by neuronal cells with surface roughness ranging from 0 to 3 μm and stiffness 10 kPa-4 MPa. This investigation reveals that the optimal surface features for neurite extension are a surface roughness of 0.5 μm and a Young's modulus between 1 and 3.5 MPa. The significance of these findings to optimize materials for nerve repair is discussed.

As an emerging additive manufacturing (AM) technique, melt electrospinning writing (MEW) is used to fabricate three-dimensional (3D) submicron filament-based scaffolds with adjustable pore size and customized structure for bone regeneration. Poly(L-lactic acid) (PLLA) scaffold with excellent biodegradability and biocompatibility is first successfully manufactured using our self-assembled MEW device. However, the ultralow cell affinity and poor bioactivity severely hamper their practical applications in bone tissue engineering. These issues are caused by the severe inherent biologically inert, hydrophobicity as well as the smooth surface of the MEW PLLA filaments. In this study, a green and robust alkaline method is applied to modify the scaffold surface and to improve the bioactivity of the MEW PLLA scaffold. Without deterioration in mechanical property but robust surface hydrophilicity, the optimal MEW PLLA scaffold shows promoted surface roughness, enhanced filament tensile modulus (~ 2 folds of the as-prepared sample), and boosted crystallizability (ultrahigh WAXD intensity). Moreover, after being cultured with KUSA-A1 cells, the 0.5 M NaOH, 2 h treated MEW PLLA scaffold exhibits higher osteoinductive ability and increased immature bone tissue amounts (3 times of controlled scaffold). Thus, the flexible surface functionalization by the specific alkaline treatment was found to be an effective method for the preparation of bioactivated MEW PLLA scaffolds with promoted bone regeneration.

Three protein microenvironment-sensitive pillar[5]arene-based fluorescent probes (3/4/5C-B) were designed and synthesized based on intramolecular charge transfer (ICT) mechanism. Unlike the majority of micromolecular ICT probes, the aforementioned probes displayed differentiated sensitivity to multiple proteins. The 7-(diethylamino)coumarin-3-formic acid (DCCA) group in the probes was essential for their sensitivity. The presence of a pillar[5]arene group was also crucial as they benefit 3/4/5C-B form complexes with the proteins, although it changed the electron density distribution of the DCCA group. 3/4/5C-B exhibited favorable carrier ability for regorafenib (REG). 4C-B had the best spatial structure for complexation. The 3/4/5C-B-REG complexes would assemble into high drug-loading fluorescent nanoparticles in a physiological environment (pH = 7.4). Such nanoparticles exhibited pH-triggered enrichment ability, which rapidly enriched REG in the acidic environment (pH = 6.0). Moreover, the complexation between 3/4/5C-B and REG maintained the live-cell membrane imaging property of the probes and the excellent targeted anticancer activity of the drug.

Conventionally, macro-textured surfaces comprising several hundred micrometer-sized patterns are used to minimize silicone-based breast implant complications, including capsular contracture. However, because of the recent cases of breast implant-associated anaplastic large cell lymphoma from macro-textured implants, there is a strong demand for nano- or micro-textured silicone implants with dimensions smaller than sub-micrometers. Herein, we propose a simple and cost-effective topographical surface modification strategy for silicone-based implants. Several hundred nanometer to sub-micrometer wide groove-type micro-textures were fabricated on a polydimethylsiloxane surface using electrospun polyvinylpyrrolidone fibers as a sacrificial template. The aligned and randomly oriented micro-textures were prepared by controlling the electrospun fiber orientation. In vitro experiments demonstrated that the micro-textured polydimethylsiloxane was cytocompatible and suppressed differentiation of fibroblasts into myofibroblasts. Importantly, the aligned micro-texture promoted the polarization of macrophages into the anti-inflammatory M2 phenotype. Long-term in vivo studies established that the micro-textures potently suppressed various factors affecting foreign body reactions by downregulating profibrotic cytokine gene expression and reducing the fibroblast and myofibroblast counts, the cells playing important roles in the immune response. Thus, the thickness and collagen density of fibrous capsules were decreased, demonstrating that the micro-textured surface effectively inhibited capsular contracture. Although the aligned micro-textures contributed to the polarization of macrophages to the M2 phenotype both in vitro and in vivo, foreign body reaction by both the aligned and randomly oriented micro-textures are similar.

The development of tissue adhesive embolization microspheres with imaging ability is one of the important methods to improve the efficacy of interventional embolization. This study reported the synthesis of iodine (I)-polyvinyl alcohol (PVA)@polydopamine (PDA) microspheres to achieve the computed tomography image, drug loading and controlled release, and the enhanced embolization of liver portal vein. The I-PVA@PDA microspheres with a diameter of 147.9 μm showed an excellent computed tomography imaging ability. Moreover, the introduction of PDA endowed the I-PVA@PDA microspheres with tissue adhesive ability and therefore the in vivo embolization effect was improved. The in vivo embolization results showed that focal necrosis of hepatocytes with necrotic cell fragments and inflammatory cell infiltration was observed in the liver tissue, proving that the I-PVA@PDA microspheres have an enhanced embolization effect than PVA particles. The I-PVA@PDA microspheres were further used to deliver and release of chemotherapeutic drugs (5-fluorouracil), which displayed an initial fast release (release amount: 29.74%) in the first 24 h and then a sustained release of 34.48% within 72 h. Moreover, as a universal platform, the PVA@PDA microspheres could combine with other imaging agents like BiS, thus holding a great potential in the interventional treatment of different diseases.

Scaffolds capable of mediating overlapping multi-cellular activities to support the different phases of wound healing while preventing scarring are essential for tissue regeneration. The potential of polysucrose as hydrogels and electrospun mats for wound healing was evaluated in vitro by seeding fibroblasts, endothelial cells and macrophages either singly or in combination. It was found that the scaffold architecture impacted cell behaviour. Electrospun mats promoted fibroblasts flattened morphology while polysucrose methacrylate (PSucMA) hydrogels promoted fibroblast spheroids formation, accentuated in the presence of endothelial cells. Hydrogels exhibited lower inflammatory response than mats and curcumin loaded scaffolds reduced TNF-α production. In vivo biocompatibility of the hydrogels tested on Wistar rats was superior to electrospun mats. In vivo wound healing studies indicated that PSucMA hydrogels integrated the surrounding tissue with better cellular infiltration and proliferation throughout the entire wound region. PSucMA hydrogels led to scarless wound closure comparable with commercially available gels.

Vascular stents are widely used in the clinical treatment of coronary heart disease, but the long-term safety still needs to be improved. Surface biological functional modification is an effective way to improve the biocompatibility and clinical performance of cardiovascular materials, but how to achieve long-term effective and precise regulation of in situ vascular intimal repair through the reasonable construction of the surface physical and chemical structure is still an important task in the current surface modification research. In this study, ECM-derived components, including laminin, heparin, and SDF-1, were incorporated into the titanium surface with a microporous structure. It was found that the modified surface could effectively control the continuous release of biomolecules. In vitro biocompatibility evaluation results showed that the constructed functional layer could effectively inhibit the activation of platelet adhesion and excessive proliferation of smooth muscle cells. In addition, the modified surface also showed the potential to induce rapid regeneration of vascular endothelium. In vivo animal tests further proved that the modified sample may contribute to inhibiting vascular intimal hyperplasia. This study provided a new approach for the surface biological function modification of Ti-based vascular stents.

Diagnosis and prognosis of Alzheimer's disease by electrochemical nanoaptasensors have recently received abundant attention. In this review, all recent nanomaterial-based electrochemical aptasensors developed to diagnose or prognosis Alzheimer's disease have been collected, categorized, and reviewed. Analytes in these aptasensors were specific biomarkers, including amyloid-β (Aβ) and tau protein, as well as other nonspecific markers (microRNAs (miRNAs), dopamine, thrombin, adenosine triphosphate (ATP), interleukin-6, α-1 antitrypsin, α-synuclein, target DNA (tDNA), and glycated albumin). The synthesis methods of the applied nanomaterials, characterization, and applications have also been considered here. Gold nanostructures were the most nanomaterials applied in the structure of considered aptasensors. The use of the most optimal nanomaterials in the structure of these diagnostic tools has been dependent on various parameters, the most important of which are the type of signal transducer and the functional group related to the biorecognition element. In general, the choice of nanomaterials in these biosensors depends on interactions between nanomaterials and other molecules or environments. Indeed, with the assistance of nanomaterials, more expansive active surfaces have been created in the interactions of aptasensors components that have played a very positive and efficient role in amplifying the output signals and increasing the analytical/diagnostic sensitivity. The diagnostic mechanisms and the interaction between the various components of aptasensors and the nanomaterials' position were also considered. The main achievements were classification, analysis, and scheming of the elements and techniques used, the possibility of comparing detection range, and the limit of detection (LOD).

Blood purification therapy is widely used in patients with renal insufficiency and severe infections, where membrane-associated thrombosis is a side effect. How to improve the hemocompatibility of dialysis membranes and reduce thrombosis is a focus of current research, in which platelets play a key role. However, few dialysis membranes that directly inhibit platelets have been developed to date. In this study, a polyethersulfone (PES) membrane was modified with ticagrelor, a platelet P2Y receptor inhibitor, and detailed characterization was performed. The ticagrelor modified PES membrane (TMPES) showed good hydrophilicity and anti-protein adsorption and significantly inhibited platelet adhesion, aggregation, and activation, which demonstrated good antithrombotic properties. In addition, the membrane had excellent red blood cell (RBC) compatibility, anticoagulant, and antiinflammatory effects, which demonstrated superior biosafety in cell and animal experiments. Therefore, the TMPES dialysis membrane could have potential in clinical applications.

Three-dimensional cellular aggregates can mimic the natural microenvironment of tissues and organs and obtaining them through controlled and reproducible processes is mandatory for scaling up and implementing drug cytotoxicity and efficacy tests, as well as tissue engineering protocols. The purpose of this work was to develop and evaluate the performance of a device with two different geometries fabricated by additive manufacturing. The methodology was based on casting a microwell array insert using a non-adhesive hydrogel to obtain highly regular microcavities to standardize spheroid formation and morphology. Spheroids of dental pulp stem cells, bone marrow stromal cells and embryonic stem cells showing high cell viability and average diameters of around 253, 220, and 500 μm, respectively, were produced using the device with the geometry considered most adequate. The cell aggregates showed sphericity indexes above 0.9 and regular surfaces (solidity index higher than 0.96). Around 1000 spheroids could be produced in a standard six-well plate. Overall, these results show that this method facilitates obtaining a large number of uniform, viable spheroids with pre-specified average diameters and through a low-cost and reproducible process for a myriad of applications.