Developing a Selection Framework for Zinc Ion-Based Biomaterial Design: Guided by the Biosafety Assessment of ZIF-8 and ZnO.

In recent years, nanomaterials have gained widespread use in the biomedical field, with ZIF-8 and ZnO emerging as promising candidates due to their remarkable performance in osteogenesis, angiogenesis, and antimicrobial therapy. However, before advancing these nanomaterials for clinical applications, it is imperative to evaluate their biocompatibility. In particular, comparing nanomaterials with similar biomedical functions is crucial for identifying the most suitable nanomaterials for further development and market entry. Our study aimed to compare the biocompatibility of nano-ZIF-8 and nano-ZnO under the same conditions. We found that nano-ZIF-8 exhibited lower toxicity both in vitro and in vivo compared to nano-ZnO. To gain insights into the underlying mechanisms responsible for this difference, we conducted further experiments to investigate lysosome damage, mitochondrial change, and the occurrence of ferroptosis. Additionally, we performed transcriptome sequencing to analyze the expression of relevant genes, thereby providing robust validation for our findings. In summary, our study highlighted the importance of evaluating nanomaterials with similar biomedical effects. Through this comparative study, we have not only shed light on the superior biocompatibility of nano-ZIF-8 over nano-ZnO, but also contributed valuable insights and methodological references for future material screening endeavors. Ultimately, our study served as a stepping stone toward the development of safer and more effective nanomaterials for various biomedical applications.

Implications of variability on medical device chemical equivalence assessment.

Chemical equivalence testing can be used to assess the biocompatibility implications of a materials or manufacturing change for a medical device. This testing can provide a relatively facile means to evaluate whether the change may result in additional or different toxicological concerns. However, one of the major challenges in the interpretation of chemical equivalence data is the lack established criteria for determining if two sets of extractables data are effectively equivalent. To address this gap, we propose a two-part approach based upon a relatively simple statistical model. First, the probability of a false positive conclusion, wherein there is an incorrectly perceived increase for a given analyte in the comparator relative to the baseline device, can be reduced to a prescribed level by establishing an appropriate acceptance criterion for the ratio of the observed means. Second, the probability of a false negative conclusion, where an actual increase in a given analyte cannot be discerned from the test results, can be minimized by specifying a limiting value of applicability based on the margin of safety (MoS) of the analyte. This approach provides a quantitative, statistically motivated method to interpret chemical equivalence data, despite the relatively high intrinsic variability and small number of replicates typically associated with a chemical characterization evaluation.

Viability and Proliferation Assessment of Gingival Fibroblasts Cultured on Silver Nanoparticle-Doped Ti-6Al-4V Surfaces.

PURPOSE: To investigate the biocompatibility of silver nanoparticle (AgNP)-doped Ti-6Al-4V surfaces by evaluating the viability and proliferation rate of human gingival fibroblasts (HGFs)-as the dominant cells of peri-implant soft tissues-seeded on the modified surfaces. MATERIALS AND METHODS: AgNPs (sizes 8 nm and 30 nm) were incorporated onto Ti-6Al-4V specimen surfaces via electrochemical deposition, using colloid silver dispersions with increasing AgNP concentrations of 100 ppm, 200 ppm, and 300 ppm. One control and six experimental groups were included in the study: (1) control (Ti-6Al-4V), (2) 8 nm/100 ppm, (3) 8 nm/200 ppm, (4) 8 nm/300 ppm, (5) 30 nm/100 ppm, (6) 30 nm/200 ppm, and (7) 30 nm/300 ppm. HGF cell primary cultures were isolated from periodontally healthy donor patients and cultured in direct contact with the group specimens for 24 and 72 hours. The cytotoxicity of AgNP-doped Ti-6Al-4V specimens toward HGF was assessed by the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) and BrdU (5-bromo-2'-deoxyuridine) assay tests. Calcein AM and ethidium homodimer (EthD-1) fluorescent stains were used to determine the live and dead cells. The morphology and attachment properties of the HGFs were determined via scanning electron microscopy (SEM). RESULTS: Energy dispersive x-ray (EDX) analysis confirmed the presence of AgNPs on the specimens. The MTT test revealed that AgNPs of both sizes and all concentrations presented a decreased cellular metabolic activity compared to the control discs. All concentrations of both sizes of AgNPs affected the cell proliferation rate compared to the control group, as revealed by the BrdU assay. Overall, cytotoxicity of the modified Ti-6Al-4V surfaces depended on cell exposure time. Observation via confocal microscopy confirmed the results of the MTT and BrdU assay tests. Specifically, most cells remained alive throughout the 72-hour culture period. SEM images revealed that adjacent cells form bonds with each other, creating confluent layers of conjugated cells. CONCLUSIONS: The findings of the present study indicate that Ti-6Al-4V surfaces modified with 8 nm and 30 nm AgNPs at concentrations of 100 ppm, 200 ppm, and 300 ppm do not produce any serious cytotoxicity toward HGFs. The initial arrest of the HGF proliferation rate recovered at 72 hours. These results on the antibacterial activity against common periodontal pathogens, in combination with the results found in a previous study by the same research group, suggest that AgNP-doped Ti-6Al-4V surfaces are potential candidates for use in implant abutments for preventing peri-implant diseases.

Assessment of hemostatic ability of biomaterial based on chitosan andEclipta prostrataL. extract.

The biomaterials based on chitosan andEclipta prostrataL. extract have been prepared by microemulsion method and solution method (with and without sodium tripolyphosphate (STPP) as a cross-linking agent). The main component inEclipta prostrataL. extract is flavonoid groups. The structure of the chitosan/extract biomaterials was studied by infrared spectroscopy. The chitosan/extract biomaterial using STPP cross-linker appeared an absorption band at 1152 cm-1attributed to the vibrations of C-O-P bonds, which proved that chitosan has crosslinked with STPP. The morphology of the biomaterials was investigated by the dynamic light scattering technique and field emission scanning electron microscopy. The obtained results showed that the particle size of the chitosan/extract biomaterials prepared by microemulsion method and solution method with STPP ranged from 68.06 nm to 1484 nm, with an average particle size of 304.9-1019 nm. The microemulsion method produced biomaterials with much smaller average particle size than the solution method using cross-linkers. The hemostatic ability of the biomaterials was better than that of the control sample based on the time of blood clotting formation and glomerular aggregation ability. The sample with the ratio ofE. prostrataL. extract: chitosan of 1:30 had the lowest hemostasis time (6 min 46 s) and its glomerular aggregation rate after 5 min was 13.05%. This indicated that the biomaterials based on chitosan andE. prostrataL. extract are promising for application in biomedicine as hemostatic materials.

Assessment of the proteome profile of decellularized human amniotic membrane and its biocompatibility with umbilical cord-derived mesenchymal stem cells.

Extracellular matrix-based bio-scaffolds are useful for tissue engineering as they retain the unique structural, mechanical, and physiological microenvironment of the tissue thus facilitating cellular attachment and matrix activities. However, considering its potential, a comprehensive understanding of the protein profile remains elusive. Herein, we evaluate the impact of decellularization on the human amniotic membrane (hAM) based on its proteome profile, physicochemical features, as well as the attachment, viability, and proliferation of umbilical cord-derived mesenchymal stem cells (hUC-MSC). Proteome profiles of decellularized hAM (D-hAM) were compared with hAM, and gene ontology (GO) enrichment analysis was performed. Proteomic data revealed that D-hAM retained a total of 249 proteins, predominantly comprised of extracellular matrix proteins including collagens (collagen I, collagen IV, collagen VI, collagen VII, and collagen XII), proteoglycans (biglycan, decorin, lumican, mimecan, and versican), glycoproteins (dermatopontin, fibrinogen, fibrillin, laminin, and vitronectin), and growth factors including transforming growth factor beta (TGF-ß) and fibroblast growth factor (FGF) while eliminated most of the intracellular proteins. Scanning electron microscopy was used to analyze the epithelial and basal surfaces of D-hAM. The D-hAM displayed variability in fibril morphology and porosity as compared with hAM, showing loosely packed collagen fibers and prominent large pore areas on the basal side of D-hAM. Both sides of D-hAM supported the growth and proliferation of hUC-MSC. Comparative investigations, however, demonstrated that the basal side of D-hAM displayed higher hUC-MSC proliferation than the epithelial side. These findings highlight the importance of understanding the micro-environmental differences between the two sides of D-hAM while optimizing cell-based therapeutic applications.

Assessment of Selected Surface and Electrochemical Properties of Boron and Strontium-Substituted Hydroxyapatites.

Tissue engineering is an interdisciplinary field of science that has been developing very intensively over the last dozen or so years. New ways of treating damaged tissues and organs are constantly being sought. A variety of porous structures are currently being investigated to support cell adhesion, differentiation, and proliferation. The selection of an appropriate biomaterial on which a patient's new tissue will develop is one of the key issues when designing a modern tissue scaffold and the associated treatment process. Among the numerous groups of biomaterials used to produce three-dimensional structures, hydroxyapatite (HA) deserves special attention. The aim of this paper was to discuss changes in the double electrical layer in hydroxyapatite with an incorporated boron and strontium/electrolyte solution interface. The adsorbents were prepared via dry and wet precipitation and low-temperature nitrogen adsorption and desorption methods. The specific surface area was characterized, and the surface charge density and zeta potential were discussed.

In vitro assessment of Momordica charantia/Hypericum perforatum oils loaded PCL/Collagen fibers: Novel scaffold for tissue engineering.

The research on tissue engineering applications has been progressing to manufacture ideal tissue scaffold biomaterials. In this study, a double-layered electrospun biofiber scaffold biomaterial including Polycaprolactone (PCL)/Collagen (COL) fibrous inner layer and PCL/ Momordica charantia (MC) and Hypericum perforatum (HP) oils fibrous outer layer was developed to manufacture a functional, novel tissue scaffold with the advantageous mechanical and biological properties. The main approach was to combine the natural perspective using medicinal oils with an engineering point of view to fabricate a potential functional scaffold for tissue engineering. Medicinal plants MC and HP are rich in functional oils and incorporation of them in a tissue scaffold will unveil their potential to augment both new tissue formation and wound healing. In this study, a novel double-layered scaffold prototype was fabricated using electrospinning technique with two PCL fiber layers, first is composed of collagen, and second is composed of oils extracted from medicinal plants. Initially, the composition of plant oils was analyzed. Thereafter the biofiber scaffold layers were fabricated and were evaluated in terms of morphology, physicochemistry, thermal and mechanical features, wettability, in vitro bio-degradability. Double-layered scaffold prototype was further analyzed in terms of in vitro biocompatibility and antibacterial effect. The medicinal oils blend provided antioxidant and antibacterial properties to the novel PCL/Oils layer. The results signify that inner PCL/COL layer exhibited advanced biodegradability of 8.5% compared to PCL and enhanced wettability with 11.7° contact angle. Strength of scaffold prototype was 5.98 N/mm2 thanks to the elastic PCL fibrous matrix. The double-layered functional biofiber scaffold enabled 92% viability after 72 h contact with fibroblast cells and furthermore provided feasible attachment sites for the cells. The functional scaffold prototype's noteworthy mechanical, chemical, and biological features enable it to be suggested as a different novel biomaterial with the potential to be utilized in tissue engineering applications.

Leveraging the Recent Advancements in GelMA Scaffolds for Bone Tissue Engineering: An Assessment of Challenges and Opportunities.

The field of bone tissue engineering has seen significant advancements in recent years. Each year, over two million bone transplants are performed globally, and conventional treatments, such as bone grafts and metallic implants, have their limitations. Tissue engineering offers a new level of treatment, allowing for the creation of living tissue within a biomaterial framework. Recent advances in biomaterials have provided innovative approaches to rebuilding bone tissue function after damage. Among them, gelatin methacryloyl (GelMA) hydrogel is emerging as a promising biomaterial for supporting cell proliferation and tissue regeneration, and GelMA has exhibited exceptional physicochemical and biological properties, making it a viable option for clinical translation. Various methods and classes of additives have been used in the application of GelMA for bone regeneration, with the incorporation of nanofillers or other polymers enhancing its resilience and functional performance. Despite promising results, the fabrication of complex structures that mimic the bone architecture and the provision of balanced physical properties for both cell and vasculature growth and proper stiffness for load bearing remain as challenges. In terms of utilizing osteogenic additives, the priority should be on versatile components that promote angiogenesis and osteogenesis while reinforcing the structure for bone tissue engineering applications. This review focuses on recent efforts and advantages of GelMA-based composite biomaterials for bone tissue engineering, covering the literature from the last five years.

Application of single cell force spectroscopy (SCFS) to the assessment of cell adhesion to peptide-decorated surfaces.

The adhesion forces of cells to peptide-coated functionalized materials were assessed through the Single Cell Force Spectroscopy (SCFS) technique in order to develop a methodology that allows the fast selection of peptide motifs that favor the interaction between cells and the biomaterial. Borosilicate glasses were functionalized using the activated vapor silanization process (AVS) and subsequently decorated with an RGD- containing peptide using the EDC/NHS crosslinking chemistry. It is shown that the RGD-coated glass induces larger attachment forces on mesenchymal stem cell cultures (MSCs), compared to the bare glass substrates. These higher forces correlate well with the enhanced adhesion of the MSCs observed on RGD-coated substrates through conventional adhesion cell cultures and inverse centrifugation tests. The methodology based on the SCFS technique presented in this work constitutes a fast procedure for the screening of new peptides or their combinations to select candidates that may enhance the response of the organism to the implant of the functionalized biomaterials.

Development and In Vivo Assessment of an Injectable Cross-Linked Cartilage Acellular Matrix-PEG Hydrogel Scaffold Derived from Porcine Cartilage for Tissue Engineering.

The cartilage acellular matrix (CAM) derived from porcine cartilage, which does not induce significant inflammation and provides an environment conducive for cell growth and differentiation, is a promising biomaterial candidate for scaffold fabrication. However, the CAM has a short period in vivo, and the in vivo maintenance is not controlled. Therefore, this study is aimed at developing an injectable hydrogel scaffold using a CAM. The CAM is cross-linked with a biocompatible polyethylene glycol (PEG) cross-linker to replace typically used glutaraldehyde (GA) cross-linker. The cross-linking degree of cross-linked CAM by PEG cross-linker (Cx-CAM-PEG) according to the ratios of the CAM and PEG cross-linker is confirmed by contact angle and heat capacities measured by differential scanning calorimetry. The injectable Cx-CAM-PEG suspension exhibits controllable rheological properties and injectability. Additionally, injectable Cx-CAM-PEG suspensions with no free aldehyde group are formed in the in vivo hydrogel scaffold almost simultaneously with injection. In vivo maintenance of Cx-CAM-PEG is realized by the cross-linking ratio. The in vivo formed Cx-CAM-PEG hydrogel scaffold exhibits certain host-cell infiltration and negligible inflammation within and near the transplanted Cx-CAM-PEG hydrogel scaffold. These results suggest that injectable Cx-CAM-PEG suspensions, which are safe and biocompatible in vivo, represent potential candidates for (pre-)clinical scaffolds.

L-cysteine aided polyaniline capped SrO2 nanoceramics: Assessment of MC3T3-E1-arbitrated osteogenesis and anti-bactericidal efficacy on the polyurethane 2D nanofibrous substrate.

Fabricating bioartificial bone graft ceramics retaining structural, mechanical, and bone induction properties akin to those of native stem-cell niches is a major challenge in the field of bone tissue engineering and regenerative medicine. Moreover, the developed materials are susceptible to microbial invasion leading to biomaterial-centered infections which might limit their clinical translation. Here, we successfully developed biomimetic porous scaffolds of polyurethane-reinforcedL-cysteine-anchored polyaniline capped strontium oxide nanoparticles to improve the scaffold's biocompatibility, osteo-regeneration, mechanical, and antibacterial properties. The engineered nanocomposite substrate PU/L-Cyst-SrO2 @PANI (0.4 wt%) significantly promotes bone repair and regeneration by modulating osteolysis and osteogenesis. ALP activity, collagen-I, ARS staining, as well as biomineralization of MC3T3-E1 cells, were used to assess the biocompatibility and cytocompatibility of the developed scaffolds in vitro, confirming that the scaffold provided a favorable microenvironment with a prominent effect on cell growth, proliferation, and differentiation. Furthermore, osteogenic protein markers were studied using qRT-PCR with expression levels of runt-related transcription factor 2 (RUNX2), secreted phosphoprotein 1 (Spp-I), and collagen type I (Col-I). The overall results suggest that PU/L-Cyst-SrO2 @PANI (0.4 wt%) scaffolds showed superior interfacial biocompatibility, antibacterial properties, load-bearing ability, and osteoinductivity as compared to pristine PU. Thus, prepared bioactive nanocomposite scaffolds perform as a promising biomaterial substrate for bone tissue regeneration.

In vitro and in vivo assessment of squeeze-cast Mg-Zn-Ca-Mn alloys for biomedical applications.

Squeeze casting of biodegradable Mg-4Zn-0.5Ca-xMn (x = 0, 0.4 or 0.8 all in weight %) alloys is a process intended to improve mechanical properties (i.e., strength and ductility), corrosion performance (i.e., resistance), and biocompatibility (i.e., little to no cytotoxicity). In this study, we found that an increased Mn content causes the dendritic microstructure of squeeze-cast Mg-4Zn-0.5Ca-xMn to become more refined and uniform, while the volume fraction of the Ca2Mg6Zn3 phase simultaneously increases. Squeeze-cast Mg-4Zn-0.5Ca-0.8Mn presents the best yield strength, ultimate tensile strength, and elongation of the alloys tested. An electrochemical corrosion test in Hanks' solution at 36.5°C demonstrates that the corrosion resistance of squeeze-cast Mg-4Zn-0.5Ca-xMn alloys show improvement at higher Mn levels. Additionally, squeeze-cast Mg-4Zn-0.5Ca alloys containing Mn exhibit favorable biocompatibility, as evidenced by cell viability studies with MC3T3-E1 cells and a local lymph node assay test. Squeeze-cast alloy specimens implanted into the skull and spine of Sprague-Dawley rats for four weeks showed no serious cytotoxicity or foreign body response; however, swelling was observed in the implantation areas of Mn-free squeeze-cast Mg-4Zn-0.5Ca alloy, while no swelling was observed in rats implanted with Mn-containing Mg-4Zn-0.5Ca alloy. These findings indicate potential applications of biodegradable, Mn-containing, squeeze-cast Mg-4Zn-0.5Ca specimens in bone-reconstruction devices given their biocompatibility, mechanical properties, and degradation profiles. STATEMENT OF SIGNIFICANCE: Bioresorbable magnesium alloys have recently gained attention as viable biomaterials for skeletal reconstruction implants. Extensive research on biodegradable Mg alloy design, synthesis, and as-cast versus post-processed material properties useful for medical applications have been reported. The squeeze-casting technique used in this study can improve the mechanical properties (i.e., strengthening) and corrosive performance (reduced rate) of bioresorbable Mg-Zn-Ca-Mn alloys. Squeeze-casting of these alloys is also expected to improve specimen microstructure, near-net-shape manufacturing, and cost (i.e., reduced). This study provides an in vitro and in vivo assessment of squeeze-cast Mg-Zn-Ca-Mn alloys for biomedical applications.

Investigation of the effects of biomaterials on proton Bragg peak and secondary neutron production by the Monte Carlo method in the slab head phantom.

Interest in proton therapy has increased in the last decade, as protons are effective to treat deeply located tumors, cause less damage to healthy tissue and allow controlling the energy to be transferred in a target-oriented manner (or energy transfer within target limits). It is known that secondary particles such as neutrons are produced by a result of nuclear interactions of protons with the target. Secondary neutrons can cause an uncontrolled dose increase in healthy tissue near the target site, and because they have a high radiobiological effectiveness, they raise the risk of secondary cancer. There are not enough studies examining the effect of biomaterials on secondary neutron production (SNP) in proton therapy. This study aims to investigate the effect of biomaterials used as implants instead of cranium in the skull on proton depth dose distribution and SNP with Monte Carlo-based PHITS code. Therefore, Bragg peaks and SNPs for 40-140 MeV energy protons were calculated and compared with the literature in a slab head phantom containing stainless steel, CoCrMo (CCM) alloy, alumina, polytetrafluoroethylene, Ti alloy, and NiTi alloy biomaterials used in cranioplasty. It was observed that the most compatible biomaterial compared to cranium for all energies is polytetrafluoroethylene. When polytetrafluoroethylene biomaterial was placed instead of the cranium in the skull, the Bragg peak position of the 100 MeV protons was decreased by 5.04% compared to that in the cranium. In this case, the energy absorbed in the polytetrafluoroethylene biomaterial increased by approximately 28% compared to the cranium, while it decreased by approx. 4% in the brain tissue. It was also observed that while SNP was 0.0501 in the cranium, it increased by almost 18% in PTFE.

Wearable Pressure Sensors Based on MXene/Tissue Papers for Wireless Human Health Monitoring.

Though the widely available, low-cost, and disposable papers have been explored in flexible paper-based pressure sensors, it is still difficult for them to simultaneously achieve ultrahigh sensitivity, low limit and broad range of detection, and high-pressure resolution. Herein, we demonstrate a novel flexible paper-based pressure sensing platform that features the MXene-coated tissue paper (MTP) sandwiched between a polyimide encapsulation layer and a printing paper with interdigital electrodes. After replacing the polyimide with weighing paper in the MTP pressure sensor, the silver interdigital electrodes can be recycled through incineration. The resulting pressure sensor with polyimide or paper encapsulation exhibits a high sensitivity of 509.5 or 344.0 kPa-1, a low limit (∼1 Pa) and a broad range (100 kPa) of detection, and outstanding stability over 10 000 loading/unloading cycles. With ultrahigh sensitivity over a wide pressure range, the flexible pressure sensor can monitor various physiological signals and human movements. Configuring the pressure sensors into an array layout results in a smart artificial electronic skin to recognize the spatial pressure distribution. The flexible pressure sensor can also be integrated with signal processing and wireless communication modules on a face mask as a remote respiration monitoring system to wirelessly detect various respiration conditions and respiratory abnormalities for early self-identification of opioid overdose, pulmonary fibrosis, and other cardiopulmonary diseases.

In Vitro Assessment of the Hydrolytic Stability of Poly(2-isopropenyl-2-oxazoline).

Poly(2-isopropenyl-2-oxazoline) (PiPOx) is emerging as a promising, versatile polymer platform to design functional materials and particularly biomaterials that rely on the hydrophilic character of the 2-oxazoline side units. To be able to assess the applicability of PiPOx in a biomedical context, it is essential to understand its stability and degradation behavior in physiological conditions. In the present work, the hydrolytic stability of PiPOx was systematically investigated as a function of pH during incubation in various buffers. PiPOx was found to be stable in deionized water (pH 6.9), to have good stability in basic conditions (pH 8 and 9), to be satisfactorily stable in neutral conditions (pH 7.4), and to have moderate to low stability in acidic conditions (decreases drastically from pH 6 to pH 1.2). At pH 4, PiPOx formed a crosslinked network in a timeframe of hours, while at pH 1.2, PiPOx was transformed to a water-soluble poly(N-(2-hydroxyethyl)methacrylamide) type of structure over the course of 2 weeks. In vitro stability assays were performed in phosphate-buffered saline (pH 7.4), simulated body fluid (SBF) (pH 7.4), simulated saliva (pH 6.4), simulated intestinal fluid (pH 6.8), and plasma (pH 7.4) revealing that PiPOx is stable in these SBFs up to 1 week of incubation. When incubated in simulated gastric fluid (pH 1.2), PiPOx exhibited a similar degradation behavior to that observed in the buffer at pH 1.2, rendering a water-soluble structure. The presented results on the stability of PiPOx will be important for future use of PiPOx for the development of drug-delivery systems and biomedical applications, such as hydrogels.

The Amine Functionalized Sugarcane Bagasse Biocomposites as Magnetically Adsorbent for Contaminants Removal in Aqueous Solution.

The method of solvothermal by one-step operation has been performed to synthesize of magnetic amine-functionalized sugarcane bagasse biocomposites (SB-MH). The obtained SB-MH contains 62.34% of Fe, 17.8 mmol/g of amine, and a magnetic property of 19.46 emu/g. The biocomposite surface area increased significantly from 1.617 to 25.789 m2/g after amine functionalization. The optimum condition of SB-MH used for Pb(II) ion removal was achieved at pH 5 for 360 min with adsorption capacity of 203.522 mg/g. The pseudo 2nd order was well-fitted to the model of Pb(II) ion adsorption. Meanwhile, other contaminant parameters number of Chemical Oxygen Demand (COD), Total Suspended Solid (TSS), and dye in wastewater were also remarkably reduced by about 74.4%, 88.0%, and 96.7%, respectively. The reusability of SB-MH with 4th repetitions showed only a slight decrease in performance of 5%. Therefore, the proposed magnetic amine-functionalized sugarcane bagasse biocomposites lead to a very potential adsorbent implemented in high scale due to high surface area, easy separation, stable materials and capability to adsorb contaminants from aqueous solution.

Safety and efficacy assessment of aerogels for biomedical applications.

The unique physicochemical properties of aerogels have made them an attractive class of materials for biomedical applications such as drug delivery, regenerative medicine, and wound healing. Their low density, high porosity, and ability to regulate the pore structure makes aerogels ideal nano/micro-structures for loading of drugs and active biomolecules. As a result of this, the number of in vitro and in vivo studies on the therapeutic efficacy of these porous materials has increased substantially in recent years and continues to be an area of great interest. However, data about their in vivo performance and safety is limited. Studies have shown that polymer-based, silica-based and some hybrid aerogels are generally regarded as safe but given that studies on the acute, subacute, and chronic toxicity for the majority of aerogel types is missing, more work is still needed. This review presents a comprehensive summary of different biomedical applications of aerogels proposed to date as well as new and innovative applications of aerogels in other areas such as decontamination. We have also reviewed their biological effect on cells and living organisms with a focus on therapeutic efficacy and overall safety (in vivo and in vitro).

Rutin-Zn(II) complex promotes bone formation - A concise assessment in human dental pulp stem cells and zebrafish.

We have assessed the molecular role of Rutin and rutin-Zn(II) complex on osteoblast differentiation and mineralization in human dental pulp cells and zebrafish model. The biocompatibility of the rutin-Zn(II) complex was determined using MTT and chick embryotoxicity assays. Alizarin red staining and ALP measurements were performed to study the osteogenic role of Rutin and rutin-Zn(II) complex at the cellular level in hDPSCs. At molecular level, following rutin and rutin-Zn(II) exposure, the mRNA expression profile of osteoblast markers such Runx2, type 1 col, OC, and ON were investigated. In addition to this, the expression of negative regulators of osteoblast development such Smad7, Smurf1, and HDAC7 waere studied by Real time RT-PCR analysis. The osteogenic role of prepared complex under in vivo was studied by an in-house zebrafish scale model followed by osteoblast differentiation markers expression profiling and Ca:P level measurement by ICP-MS. Rutin and the rutin-Zn(II) complex were found to be non-toxic till 10 µM and increased the expression of osteoblast differentiation marker genes. It also enhanced calcium deposition in both in vitro and in vivo models. Osteogenic property of rutin-Zn(II) in hDPSCs was found be mediated by Smad7, Smurf1, and HDAC7 and enhancing Runx2 expression. Our study warrants the possible use of rutin-Zn(II) as naïve agent or in combination with other bone scaffolding systems/materials for bone tissue engineering applications.

The effect of pores and connections geometries on bone ingrowth into titanium scaffolds: an assessment based on 3D microCT images.

In order to support bone tissue regeneration, porous biomaterial implants (scaffolds) must offer chemical and mechanical properties, besides favorable fluid transport. Titanium implants provide these requirements, and depending on their microstructural parameters, the osteointegration process can be stimulated. The pore structure of scaffolds plays an essential role in this process, guiding fluid transport for neo-bone regeneration. The objective of this work was to analyze geometric and morphologic parameters of the porous microstructure of implants and analyze their influences in the bone regeneration process, and then discuss which parameters are the most fundamental. Bone ingrowths into two different sorts of porous titanium implants were analyzed after 7, 14, 21, 28, and 35 incubation days in experimental animal models. Measurements were accomplished with x-ray microtomography image analysis from rabbit tibiae, applying a pore-network technique. Taking into account the most favorable pore sizes for neo-bone regeneration, a novel approach was employed to assess the influence of the pore structure on this process: the analyses were carried out considering minimum pore and connection sizes. With this technique, pores and connections were analyzed separately and the influence of connectivity was deeply evaluated. This investigation showed a considerable influence of the size of connections on the permeability parameter and consequently on the neo-bone regeneration. The results indicate that the processing of porous scaffolds must be focused on deliver pore connections that stimulate the transport of fluids throughout the implant to be applied as a bone replacer.

Assessment of novel surgical procedures using decellularised muscle and bioactive ceramic: a histological analysis.

Tissue regeneration and neovascularisation in cases of major bone loss is a challenge in maxillofacial surgery. The hypothesis of the present study is that the addition of resorbable bioactive ceramic Silica Calcium Phosphate Cement (SCPC) to Declluraized Muscle Scaffold (DSM) can expedite bone formation and maturation. Two surgical defect models were created in 18 nude transgenic mice. Group 1(n = 6), with a 2-mm decortication calvarial defect, was treated with a DSM/SCPC sheet over the corticated bone as an onlay then seeded with human Mesenchymal Stromal Cells hMSC in situ. In Group 2 (n = 6), a critical size (4 mm) calvarial defect was made and grafted with DSM/SCPC/in situ human bone marrow stromal cells (hMSCs). The control groups included Group 3 (n = 3) animals, with a 2-mm decortication defect treated with an onlay DSM sheet, and Group 4 (n = 3) animals, treated with critical size defect grafted with plain DSM. After 8 weeks, bone regeneration in various groups was evaluated using histology, immunohistochemistry and histomorphometry. New bone formation and maturation was superior in groups treated with DSM/SCPC/hMSC. The DMS/SCPC scaffold has the ability to augment and induce bone regeneration and neovascularisation in cases of major bone resorption and critical size defects.