3D hydrogel/ bioactive glass scaffolds in bone tissue engineering: Status and future opportunities.

Repairing significant bone defects remains a critical challenge, raising the clinical demand to design novel bone biomaterials that incorporate osteogenic and angiogenic properties to support the regeneration of vascularized bone. Bioactive glass scaffolds can stimulate angiogenesis and osteogenesis. In addition, natural or synthetic polymers exhibit structural similarity with extracellular matrix (ECM) components and have superior biocompatibility and biodegradability. Thus, there is a need to prepare composite scaffolds of hydrogels for vascularized bone, which incorporate to improve the mechanical properties and bioactivity of natural polymers. In addition, those composites' 3-dimensional (3D) form offer regenerative benefits such as direct doping of the scaffold with ions. This review presents a comprehensive discussion of composite scaffolds incorporated with BaG, focusing on their effects on osteo-inductivity and angiogenic properties. Moreover, the adaptation of the ion-doped hydrogel composite scaffold into a 3D scaffold for the generation of vascularized bone tissue is exposed. Finally, we highlight the challenges and future of manufacturing such biomaterials.

Calcium-based nanomaterials and their interrelation with chitosan: optimization for pCRISPR delivery.

There have been numerous advancements in the early diagnosis, detection, and treatment of genetic diseases. In this regard, CRISPR technology is promising to treat some types of genetic issues. In this study, the relationship between calcium (due to its considerable physicochemical properties) and chitosan (as a natural linear polysaccharide) was investigated and optimized for pCRISPR delivery. To achieve this, different forms of calcium, such as calcium nanoparticles (CaNPs), calcium phosphate (CaP), a binary blend of calcium and chitosan including CaNPs/Chitosan and CaP/Chitosan, as well as their tertiary blend including CaNPs-CaP/Chitosan, were prepared via both routine and green procedures using Salvia hispanica to reduce toxicity and increase nanoparticle stability (with a yield of 85%). Such materials were also applied to the human embryonic kidney (HEK-293) cell line for pCRISPR delivery. The results were optimized using different characterization techniques demonstrating acceptable binding with DNA (for both CaNPs/Chitosan and CaNPs-CaP/Chitosan) significantly enhancing green fluorescent protein (EGFP) (about 25% for CaP/Chitosan and more than 14% for CaNPs-CaP/Chitosan). Supplementary Information: The online version contains supplementary material available at 10.1007/s40097-021-00446-1.

Bio-multifunctional noncovalent porphyrin functionalized carbon-based nanocomposite.

Herein, in a one-pot method, the reduced graphene oxide layers with the assistance of multiwalled carbon nanotubes were decorated to provide a suitable space for the in situ growth of CoNi2S4, and the porphyrins were incorporated into the layers as well to increase the sensitivity of the prepared nanostructure. The prepared nanocomposite can establish π-π interactions between the genetic material and on the surface of porphyrin rings. Also, hydrogen bonds between genetic domains and the porphyrin' nitrogen and the surface hydroxyl groups are probable. Furthermore, the potential donor-acceptor relationship between the d7 transition metal, cobalt, and the genetic material provides a suitable way to increase the interaction and gene loading , and transfections. The reason for this phenomenon was optimized to increase the EGFP by up to 17.9%. Furthermore, the sensing ability of the nanocomposite towards H2O2 was investigated. In this regard, the limit of detection of the H2O2 obtained 10 µM. Also, the in situ biosensing ability in the HEK-293 and PC12 cell lines was evaluated by the addition of PMA. The nanocomposite showed the ability to detect the released H2O2 after adding the minimum amount of 120 ng/mL of the PMA.

Turning Toxic Nanomaterials into a Safe and Bioactive Nanocarrier for Co-delivery of DOX/pCRISPR.

Hybrid bioactive inorganic-organic carbon-based nanocomposites of reduced graphene oxide (rGO) nanosheets enlarged with multi-walled carbon nanotubes (MWCNTs) were decorated to provide a suitable space for in situ growth of CoNi2S4 and green-synthesized ZnO nanoparticles. The ensuing nanocarrier supplied π-π interactions between the DOX drug and a stabilizing agent derived from leaf extracts on the surface of ZnO nanoparticles and hydrogen bonds; gene delivery of (p)CRISPR was also facilitated by chitosan and alginate renewable macromolecules. Also, these polymers can inhibit the potential interactions between the inorganic parts and cellular membranes to reduce the potential cytotoxicity. Nanocomposite/nanocarrier analyses and sustained DOX delivery (cytotoxicity analyses on HEK-293, PC12, HepG2, and HeLa cell lines after 24, 48, and 72 h) were indicative of an acceptable cell viability of up to 91.4 and 78.8% after 48 at low and high concentrations of 0.1 and 10 µg/mL, respectively. The MTT results indicate that by addition of DOX to the nanostructures, the relative cell viability increased after 72 h of treatment; since the inorganic compartments, specifically CoNi2S4, are toxic, this is a promising route to increase the bioavailability of the nanocarrier before reaching the targeted cells. Nanosystems were tagged with (p)CRISPR for co-transfer of the drug/genes, where confocal laser scanning microscopy (CLSM) pictures of the 4',6-diamidino-2-phenylindole (DAPI) were indicative of appropriate localization of DOX into the nanostructure with effective cell and drug delivery at varied pH. Also, the intrinsic toxicity of CoNi2S4 does not affect the morphology of the cells, which is a breakthrough. Furthermore, the CLSM images of the HEK-293 and HeLa cell displayed effective transport of (p)CRISPR into the cells with an enhanced green fluorescent protein (EGFP) of up to 8.3% for the HEK-293 cell line and 21.4% for the HeLa cell line, a record. Additionally, the specific morphology of the nanosystems before and after the drug/gene transport events, via images by TEM and FESEM, revealed an intact morphology for these biopolymers and their complete degradation after long-time usage.

Green Synthesis of ZnO NPs via Salvia hispanica: Evaluation of Potential Antioxidant, Antibacterial, Mammalian Cell Viability, H1N1 Influenza Virus Inhibition and Photocatalytic Activities.

Among different forms of metallic nanoparticles (NPs), zinc oxide (ZnO) NPs with a very special bandgap of 3.37 eV and considerable binding energy of excitation (60 meV at room temperature), have been classified as high-tech nanoparticles. This study aimed to synthesize ZnO NPs using the extract from Salvia hispanica leaves. The synthesized nanoparticles were fully characterized and the photocatalytic activity was evaluated through the degradation of methylene blue. Additionally, the potential in vitro biological activities of such ZnO NPs in terms of their antibacterial activity were determined, as well as their antioxidant (30 minutes), antiviral (48 hours) and mammalian cell viability properties (48 and 72 hours). This study is the first investigation into the synthesis of such green ZnO NPs mediated by this plant extract, in which both photocatalytic and biomedical properties were found to be promising. The IC50 values for the antibacterial activities were found to be around 17.4 µg mL-1 and 28.5 µg mL-1 for S. aureus and E. coli, respectively, and the antioxidant activity was comparable with the standard BHT. However, the H1N1 inhibition rate using the present green ZnO NPs was lower than oseltamivir (up to about 40% for ZnO NPs and above 90% for oseltamivir) which was expected since it is a drug, but was higher than many synthetic nanoparticles reported in the literature. In addition, the mammalian cell viability assay showed a higher than 80% cellular viability in the presence of 5, 10 and 20 µg mL-1 nanoparticles, and showed a higher than 50% cellular viability in the presence of 50 and 75 µg mL-1 nanoparticles. In this manner, this study showed that these green ZnO NPs should be studied for a wide range of medical applications.

High-Gravity-Assisted Green Synthesis of NiO-NPs Anchored on the Surface of Biodegradable Nanobeads with Potential Biomedical Applications.

Here, an unprecedented synthesis method for nickel oxide nanoparticles (NiO-NPs) was facilitated using Salvia hispanica leaf extracts with the assistance of a high gravity rotating packed bed (RPB) system that enabled fast mass transfer and molecular mixing. The synthesized nanoparticles were anchored on the surface of biodegradable chitosan nanobeads and their photocatalytic activity was evaluated by the degradation of methylene blue. Additionally, the potential biological activities of NiO-NPs in terms of antibacterial (Staphylococcus aureus and Escherichia coli for 24 hours), cytotoxicity (using the PC12 cell line for 24 and 72 hours), and antioxidant activities (based on the discoloration of the methanolic solution of DPPH) were assessed. This novel approach for NiO-NPs@Chitosan synthesis as mediated by a renewable plant extract and facilitated by a high-gravity method, led to the greener synthesis of nanoparticles with significant antibacterial and photocatalytic properties.