Formation of Transient Amorphous Calcium Carbonate Precursor in Quail Eggshell Mineralization: An In Vitro Study

Ovomucoid gene polymorphism and its influence on quality changes at various storage timepoint of eggs from two strains of Japanese quail

During storage, irreversible changes occur in eggs, resulting in a decline in their quality, predominantly affecting the albumen. Ovomucoid, a major protein found in egg white, belongs to the Kazal-type serine proteinase inhibitors and serves to protect the embryo from microorganisms. Notably, in chicken eggs, it is a significant allergen. There is a possibility that its polymorphism also influences the quality and stability of table eggs. Hence, this study aimed to evaluate the potential effect of polymorphism in the ovomucoid gene and protein on quality changes during the storage of eggs derived from 2 strains of Japanese quail, encompassing various utility types. Eggs from selected females of laying and meat-type breeds were stored for 14 wk, with egg quality traits assessed 10 times during this duration. DNA was isolated from each female, and sequencing was conducted on all exons of the ovomucoid gene. In total, 5 SNPs were identified in exons and adjacent intronic sequences, with SNP1 (13:12355585), SNP4 (13:12356594), and SNP5 (13:12358538) leading to amino acid substitutions in the ovomucoid protein. Notably, all SNPs except SNP5 were identified in the ovomucoid gene of Japanese quail for the first time. The results demonstrated that in the F33 strain, SNP1, SNP3, and SNP4 exhibited significant associations with egg weight, whereas in the S22 strain, SNP5 significantly affected yolk color and various eggshell quality traits, including eggshell weight, eggshell thickness, and breaking strength, throughout the storage period. Furthermore, a haplotype block containing 2 SNPs (3 and 4) was identified, exhibiting 2 distinct haplotypes that significantly affected egg weight, eggshell weight, and breaking strength at various storage time points during egg quality analyses. These findings provide novel insights into the genetic basis of egg quality during storage and have the potential to be integrated into breeding programs for these strains.

Antimicrobial Proteins and Peptides in Avian Eggshell: Structural Diversity and Potential Roles in Biomineralization

The calcitic avian eggshell provides physical protection for the embryo during its development, but also regulates water and gaseous exchange, and is a calcium source for bone mineralization. The calcified eggshell has been extensively investigated in the chicken. It is characterized by an inventory of more than 900 matrix proteins. In addition to proteins involved in shell mineralization and regulation of its microstructure, the shell also contains numerous antimicrobial proteins and peptides (AMPPs) including lectin-like proteins, Bacterial Permeability Increasing/Lipopolysaccharide Binding Protein/PLUNC family proteins, defensins, antiproteases, and chelators, which contribute to the innate immune protection of the egg. In parallel, some of these proteins are thought to be crucial determinants of the eggshell texture and its resulting mechanical properties. During the progressive solubilization of the inner mineralized eggshell during embryonic development (to provide calcium to the embryo), some antimicrobials may be released simultaneously to reinforce egg defense and protect the egg from contamination by external pathogens, through a weakened eggshell. This review provides a comprehensive overview of the diversity of avian eggshell AMPPs, their three-dimensional structures and their mechanism of antimicrobial activity. The published chicken eggshell proteome databases are integrated for a comprehensive inventory of its AMPPs. Their biochemical features, potential dual function as antimicrobials and as regulators of eggshell biomineralization, and their phylogenetic evolution will be described and discussed with regard to their three-dimensional structural characteristics. Finally, the repertoire of chicken eggshell AMPPs are compared to orthologs identified in other avian and non-avian eggshells. This approach sheds light on the similarities and differences exhibited by AMPPs, depending on bird species, and leads to a better understanding of their sequential or dual role in biomineralization and innate immunity.

Recent Advances in Zinc Oxide Nanoparticles (ZnO NPs) for Cancer Diagnosis, Target Drug Delivery, and Treatment

Cancer is regarded as one of the most deadly and mirthless diseases and it develops due to the uncontrolled proliferation of cells. To date, varieties of traditional medications and chemotherapies have been utilized to fight tumors. However, their immense drawbacks, such as reduced bioavailability, insufficient supply, and significant adverse effects, make their use limited. Nanotechnology has evolved rapidly in recent years and offers a wide spectrum of applications in the healthcare sectors. Nanoscale materials offer strong potential for curing cancer as they pose low risk and fewer complications. Several metal oxide NPs are being developed to diagnose or treat malignancies, but zinc oxide nanoparticles (ZnO NPs) have remarkably demonstrated their potential in the diagnosis and treatment of various types of cancers due to their biocompatibility, biodegradability, and unique physico-chemical attributes. ZnO NPs showed cancer cell specific toxicity via generation of reactive oxygen species and destruction of mitochondrial membrane potential, which leads to the activation of caspase cascades followed by apoptosis of cancerous cells. ZnO NPs have also been used as an effective carrier for targeted and sustained delivery of various plant bioactive and chemotherapeutic anticancerous drugs into tumor cells. In this review, at first we have discussed the role of ZnO NPs in diagnosis and bio-imaging of cancer cells. Secondly, we have extensively reviewed the capability of ZnO NPs as carriers of anticancerous drugs for targeted drug delivery into tumor cells, with a special focus on surface functionalization, drug-loading mechanism, and stimuli-responsive controlled release of drugs. Finally, we have critically discussed the anticancerous activity of ZnO NPs on different types of cancers along with their mode of actions. Furthermore, this review also highlights the limitations and future prospects of ZnO NPs in cancer theranostic.

Pearl Powder-An Emerging Material for Biomedical Applications: A Review

Pearl powder is a well-known traditional Chinese medicine for a variety of indications from beauty care to healthcare. While used for over a thousand years, there has yet to be an in-depth understanding and review in this area. The use of pearl powder is particularly growing in the biomedical area with various benefits reported due to the active ingredients within the pearl matrix itself. In this review, we focus on the emerging biomedical applications of pearl powder, touching on applications of pearl powder in wound healing, bone repairing, treatment of skin conditions, and other health indications.

Avian eggshell biomineralization: an update on its structure, mineralogy and protein tool kit

BACKGROUND

The avian eggshell is a natural protective envelope that relies on the phenomenon of biomineralization for its formation. The shell is made of calcium carbonate in the form of calcite, which contains hundreds of proteins that interact with the mineral phase controlling its formation and structural organization, and thus determine the mechanical properties of the mature biomaterial. We describe its mineralogy, structure and the regulatory interactions that integrate the mineral and organic constituents during eggshell biomineralization. Main Body. We underline recent evidence for vesicular transfer of amorphous calcium carbonate (ACC), as a new pathway to ensure the active and continuous supply of the ions necessary for shell mineralization. Currently more than 900 proteins and thousands of upregulated transcripts have been identified during chicken eggshell formation. Bioinformatic predictions address their functionality during the biomineralization process. In addition, we describe matrix protein quantification to understand their role during the key spatially- and temporally- regulated events of shell mineralization. Finally, we propose an updated scheme with a global scenario encompassing the mechanisms of avian eggshell mineralization.

CONCLUSION

With this large dataset at hand, it should now be possible to determine specific motifs, domains or proteins and peptide sequences that perform a critical function during avian eggshell biomineralization. The integration of this insight with genomic data (non-synonymous single nucleotide polymorphisms) and precise phenotyping (shell biomechanical parameters) on pure selected lines will lead to consistently better-quality eggshell characteristics for improved food safety. This information will also address the question of how the evolutionary-optimized chicken eggshell matrix proteins affect and regulate calcium carbonate mineralization as a good example of biomimetic and bio-inspired material design.

Molecular dynamics simulation of protein-mediated biomineralization of amorphous calcium carbonate

The protein-mediated biomineralization of calcium carbonate (CaCO₃) in living organisms is primarily governed by critical interactions between the charged amino acids of the protein, solvent, calcium (Ca²⁺) and carbonate (CO₃²⁻) ions. The present article investigates the molecular mechanism of lysozyme-mediated nucleation of amorphous calcium carbonate (ACC) using molecular dynamics and metadynamics simulations. The results reveal that, by acting as nucleation sites, the positively charged side chains of surface-exposed arginine residues form hydrogen bonds with carbonates and promote aggregation of ions around them leading to the formation and growth of ACC on the protein surface. The newly formed ACC patches were found to be less hydrated due to ion aggregation-induced expulsion of water from the nucleation sites. Despite favorable electrostatic interactions of the negatively charged side chains of aspartate and glutamate with calcium ions, these residues contribute minimally to the growth of ACC on protein surface. The activation barrier for the growth of partially hydrated ACC patches on lysozymes was determined from the free energy profiles obtained from metadynamics simulations.

The protein-mediated biomineralization of calcium carbonate (CaCO₃) in living organisms is primarily governed by critical interactions between the charged amino acids of the protein, solvent, calcium (Ca²⁺) and carbonate (CO₃²⁻) ions.

Biomineralization in modern avian calcified eggshells: similarity versus diversity

Avian eggshells are composed of several layers made of organic compounds and a mineral phase (calcite), and the general structure is basically the same in all species. A comparison of the structure, crystallography, and chemical composition shows that despite an overall similarity, each species has its own structure, crystallinity, and composition. Eggshells are a perfect example of the crystallographic versus biological concept of the formation and growth mechanisms of calcareous biominerals: the spherulitic-columnar structure is described as "a typical case of competitive crystal growth", but it is also said that the eggshell matrix components regulate eggshell mineralization. Electron back scattered diffraction (EBSD) analyses show that the crystallinity differs between different species. Nevertheless, the three layers are composed of rounded granules, and neither facets nor angles are visible. In-situ analyses show the heterogeneous distribution of chemical elements throughout the thickness of single eggshell. The presence of organic matrices other than the outer and inner membranes in eggshells is confirmed by thermograms and infrared spectrometry, and the differences in quality and quantity depend on the species. Thus, as in other biocrystals, crystal growth competition is not enough to explain these differences, and there is a strong biological control of the eggshell secretion.

Copper-polyaniline nanocomposite: Role of physicochemical properties on the antimicrobial activity and genotoxicity evaluation

Copper nanoparticles (Cu NPs) have proven to own excellent antimicrobial efficacy, but the problems of easy oxidation and aggregation limit their practical application. Here, nanocomposite based on polyaniline (PANI) and Cu NPs solved this problem and brought additional physicochemical properties that are markedly advantageous for antimicrobial applications. Current work exploits this potential, to examine its time- and concentration-dependent antimicrobial activity, employing E. coli, S. aureus, and C. albicans as a model microbial species. Regarding the presence of polaronic charge carriers in the fibrous polyaniline network, effects of Cu NPs' size and their partially oxidized surfaces (the data were confirmed by HRTEM, FESEM, XRD, Raman and XPS analysis), as well as rapid copper ions release, Cu-PANI nanocomposite showed efficient bactericidal and fungicidal activities at the concentrations ≤1 ppm, within the incubation time of 2 h. Beside the quantitative analysis, the high levels of cellular disruption for all tested microbes were evidenced by atomic force microscopy. Moreover, the minimum inhibitory and bactericidal concentrations of the Cu-PANI nanocomposite were lower than those reported for other nanocomposites. Using such low concentrations is recognized as a good way to avoid its toxicity toward the environment. For this purpose, Cu-PANI nanocomposite is tested for its genotoxicity and influence on the oxidative status of the human cells in vitro.

Pectin-guar gum-zinc oxide nanocomposite enhances human lymphocytes cytotoxicity towards lung and breast carcinomas

Pectin-guar gum-zinc oxide (PEC-GG-ZnO) nanocomposite was prepared by precipitation technique. The composite was characterized by using FT-IR, XRD, HRTEM, SAED, EDS, and SEM. TEM images showed the hexagonal shape of nanocomposite with the size range of 50-70 nm. Further, PEC-GG-ZnO was used as an immunomodulator for the first time to improve the cancer cells killing capabilities of human peripheral-blood lymphocytes (PBL). The lymphocyte proliferation assay proved the immunostimulatory property of the PEC-GG-ZnO which increased with the increase in concentration (25 μg/ml to 200 μg/ml). ELISA detection confirmed a significant increase in the release of IFN-γ, IL-2 and TNF-α cytokines and flow cytometry analysis revealed enhanced expression of CD3, CD8, and CD56 after treating PBL with PEC-GG-ZnO as compared to PEC and GG treatment. Moreover, we also found that nanocomposite pretreated human PBL displayed enhanced cytotoxicity towards lung (A549) and breast carcinoma (MCF-7) cells as compared to untreated PBL. The microcytotoxicity assay also demonstrated that with increase in effector: target ratios from 2.5:1 to 20:1, there was an increase in the cancer cell death. Taken together, the current data corroborates the immunostimulatory activities of PEC-GG-ZnO, a novel nanocomposite, hence it can serve as a promising cancer therapeutic agent.

Biofunctionalized peptide nanofiber-based composite scaffolds for bone regeneration

Bone tissue had moderate self-healing capabilities, but biomaterial scaffolds were required for the repair of some defects such as large bone defects. Peptide nanofiber scaffolds demonstrated important potential in regenerative medicine. Functional modification and controlled release of signal molecules were two significant approaches to increase the bioactivity of biofunctionalized peptide nanofiber scaffolds, but peptide scaffolds were limited by insufficient mechanical strength. Thus, it was necessary to combine peptide scaffolds with other materials including polymers, hydroxyapatite, demineralized bone matrix (DBM) and metal materials based on the requirement of different bone defects. As the development of peptide-based composite scaffolds continued to evolve, ultimate translation to the clinical environment may allow for improved therapeutic outcomes for bone repair.

Biomimetic polyurethane/TiO2 nanocomposite scaffolds capable of promoting biomineralization and mesenchymal stem cell proliferation

Scaffolds with extracellular matrix-like fibrous morphology, suitable mechanical properties, biomineralization capability, and excellent cytocompatibility are desired for bone regeneration. In this work, fibrous and degradable poly(ester urethane)urea (PEUU) scaffolds reinforced with titanium dioxide nanoparticles (nTiO2) were fabricated to possess these properties. To increase the interfacial interaction between PEUU and nTiO2, poly(ester urethane) (PEU) was grafted onto the nTiO2. The scaffolds were fabricated by electrospinning and exhibited fiber diameter of <1μm. SEM and EDX mapping results demonstrated that the PEU modified nTiO2 was homogeneously distributed in the fibers. In contrast, severe agglomeration was found in the scaffolds with unmodified nTiO2. PEU modified nTiO2 significantly increased Young's modulus and tensile stress of the PEUU scaffolds while unmodified nTiO2 significantly decreased Young's modulus and tensile stress. The greatest reinforcement effect was observed for the scaffold with 1:1 ratio of PEUU and PEU modified nTiO2. When incubating in the simulated body fluid over an 8-week period, biomineralization was occurred on the fibers. The scaffolds with PEU modified nTiO2 showed the highest Ca and P deposition than pure PEUU scaffold and PEUU scaffold with unmodified nTiO2. To examine scaffold cytocompatibility, bone marrow-derived mesenchymal stem cells were cultured on the scaffold. The PEUU scaffold with PEU modified nTiO2 demonstrated significantly higher cell proliferation compared to pure PEUU scaffold and PEUU scaffold with unmodified nTiO2. The above results demonstrate that the developed fibrous nanocomposite scaffolds have potential for bone tissue regeneration.

Simple fabrication of rough halloysite nanotubes coatings by thermal spraying for high performance tumor cells capture

Here, we reported a fast, low-cost, and effective fabrication method of large-area and rough halloysite nanotubes (HNTs) coatings by thermal spraying of HNTs ethanol dispersions. A uniform HNTs coating with high transparence is achieved with tailorable surface roughness and thickness. Compared with normal cells, the tumor cells can be captured effectively with high capture yield by the HNTs coatings (expect HeLa cells), which is attributed to the enhanced topographic interactions between HNTs coating and cancer cells. HNTs coating formed from 2.5% ethanol dispersions shows the highest tumor cells capture yeild (90%), which is related to the appropriate roughness and anti-EpCAM conjugation. The capture yield of HNTs coating towards MCF-7 cells can be further improved to 93% within 2h under dynamic shear using a peristaltic pump. The capture yield increases with the incubation time, and the flow rate with 1.25mL/min leads to the maximum capture yield. The HNTs coatings are also effective for capture of tumor cells spiked in artificial blood samples and blood samples from patients with metastatic breast cancer. More than 90% targeted MCF-7 cells and very small amounts of white blood cells are captured by the anti-EpCAM conjugated HNTs coatings from a blood sample. HNTs are further loaded anticancer drug doxorubicin (DOX) and then thermally sprayed into coatings. The MCF-7 cells captured on DOX loaded HNTs coating display significant membrane rupture characteristic and only 3% cell viability after 16h. The high capture efficiency of tumor cells by HNTs coating fabricated by the thermal spraying method makes them show promising applications in clinical circulating tumor cells capture for early diagnosis and monitoring of cancer patients. The high killing ability of the DOX loaded HNTs coating can also be designed as an implantable therapeutic device for preventing tumor metastasis.

Development of porous chitosan/tripolyphosphate scaffolds with tunable uncross-linking primary amine content for bone tissue engineering

The primary amine along the chitosan backbone plays a key role in biomedical applications. Although chitosan-based porous scaffolds have been widely used in tissue engineering, it remains very challenging to regulate uncross-linking primary amine content (C_N) in scaffolds in order to realize particular mechanical and biological properties. In the present study, chitosan/tripolyphosphate (TPP) scaffolds with controlled C_N (i.e., degree of cross-linking) were prepared based on the ionic-dependent solubility of chitosan together with the freezing process. The effects of the concentration of TPP (C_TPP) and NaCl (C_NaCl) in the cross-linking solution on C_N were studied by infrared spectroscopy, ninhydrin assays and elemental analysis. The results showed that C_N decreased with increasing C_TPP and decreasing C_NaCl. C_N affected physicomechanical properties such as swelling behavior and the mechanical strength of the chitosan/TPP scaffolds. The uncross-linking primary amine in scaffolds can be used for chemical and biological modifications. The protein loading of the scaffolds demonstrated that the pH-responsive adsorption and release behavior was influenced by C_N. Cell experiments also illustrated that C_N affected the proliferation of bone marrow mesenchymal stem cells (BM-MSCs). All of these results indicate that these porous chitosan/TPP scaffolds containing uncross-linking primary amines are potentially useful for applications in regenerative bone medicine.

pH-responsive mesoporous ZSM-5 zeolites/chitosan core-shell nanodisks loaded with doxorubicin against osteosarcoma

Oral or intravenous chemotherapy is an important strategy to treat metastatic cancer, but it may cause systemic toxicity for healthy tissue. Herein, we for the first time fabricated mesoporous ZSM-5 zeolites/chitosan core-shell nanodisks loaded with doxorubicin (ZSM-5/CS/DOX) as drug delivery systems against osteosarcoma. The mesoporous ZSM-5 zeolites exhibited disk-like shapes with thicknesses of 100nm and diameters of 300nm, and the mesopores with pore sizes of 3.75nm were originated from desilication treatment. The pH-responsive ZSM-5/CS/DOX nanodisks possessed a great drug loading efficiency of 97.7%, and their controlled release trends of DOX were fitted well with the Korsmeyer-Peppas model. The DOX could be efficiently released the ZSM-5/CS/DOX nanodisks after cellular endocytosis and induced cancer cells apoptosis. Moreover, the pH-responsive drug carriers led to efficient tumor inhibition with low side effects, especially cardiac toxicity, as confirmed by pharmacokinetic study, serological examination and H&E staining assays. Therefore, the ZSM-5/CS/DOX nanodisks are a promising pH-responsive drug carrier for targeted cancer therapy.

Hybrid PCL/CaCO3 scaffolds with capabilities of carrying biologically active molecules: Synthesis, loading and in vivo applications

Designing advanced biomaterials for tissue regeneration with drug delivery and release functionalities remains a challenge in regenerative medicine. In this research, we have developed novel composite scaffolds based on polymeric polycaprolactone fibers coated with porous calcium carbonate structures (PCL/CaCO₃) for tissue engineering and have shown their drug delivery and release in rats. In vivo biocompatibility tests of PCL/CaCO₃ scaffolds were complemented with in vivo drug release study, where tannic acid (TA) was used as a model drug. Release of TA from the scaffolds was realized by recrystallization of the porous vaterite phase of calcium carbonate into the crystalline calcite. Cell colonization and tissue vascularization as well as transplantability of developed PCL/CaCO₃+TA scaffolds were observed. Detailed study of scaffold transformations during 21-day implantation period was followed by scanning electron microscopy and X-ray diffraction studies before and after in vivo implantation. The presented results demonstrate that PCL/CaCO₃ scaffolds are attractive candidates for implants in bone regeneration and tissue engineering with a possibility of loading biologically active molecules and controlled release.

Optimization of the composition and dosage of PEGylated polyethylenimine-entrapped gold nanoparticles for blood pool, tumor, and lymph node CT imaging

Gold nanoparticles (Au NPs) with a high X-ray attenuation coefficient have a good potential in CT imaging applications. Here, we report the design and synthesis of Au NPs entrapped within polyethylene glycol (PEG)-modified branched polyethyleneimine (PEI) with varying the initial Au salt/PEI molar ratios and with the remaining PEI surface amines being acetylated for blood pool, lung tumor and lymph node CT imaging. The formed unacetylated and acetylated PEGylated PEI-entrapped Au NPs (Au PENPs) were characterized via different methods. We show that the PEGylated PEI is an effective template to entrap Au NPs having a uniform size ranging from 1.7nm to 4.4nm depending on the Au salt/PEI molar ratio. After optimization of the composition-dependent X-ray attenuation effect, we then selected {(Au⁰)₁₀₀-PEI·NHAc-mPEG} NPs for biological testing and show that the particles have good cytocompatibility in the given concentration range and can be used as a contrast agent for effective CT imaging of the blood pool of rats, lung cancer model of nude mice and lymph node of rabbits after intravenous injection. For each application, the injected dosage of the particles was optimized. In addition, the {(Au⁰)₁₀₀-PEI·NHAc-mPEG} NPs could be excreted out of the body with time. Our results indicate that the formed Au PENPs with an appropriate composition and dosage hold a great promise to be used for CT imaging of various biosystems.

Glucose functionalized carbon quantum dot containing organic radical for optical/MR dual-modality bioimaging

The organic paramagnetic compounds nitroxides have great potential as magnetic resonance imaging (MRI) contrast agents. Herein, we report the synthesis and characterization of glucose modified carbon quantum dot containing 2,2,6,6-tetramethyl-piperidinooxy (TEMPO) for targeted bimodal MR/optical imaging of tumor cells. CQD-TEMPO-Glu shows the greatest potentials for bioimaging applications in view of low cytotoxicity, good biocompatibility, green fluorescence emission and high T1 relaxivities. The in vitro MR and optical imaging results confirm enhanced cellular internalization of CQD-TEMPO-Glu in cancer cells through GLUT mediated endocytosis. These results confirm that CQD-TEMPO-Glu is expected to be widely exploited as dual-modal contrast for cancer imaging.

Visible light-assisted efficient degradation of dye pollutants with biomass-supported TiO2 hybrids

The objective of this work was to develop a novel organic-inorganic hybrid nanomaterial from agricultural biomass waste for environmental applications. The sugarcane bagasse (SB) supported TiO₂ hybrids were firstly synthesized via a sol-gel method. A series of characterizations were carried out to reveal the structures and components of obtained hybrids. Due to organic-inorganic hybrid (OIH) effect and element doping, the SB-TiO₂ hybrid can expand its optical absorbance ranging from ultraviolet to visible light. The optimal hybrid catalyst prepared with SB doping amount of 2g in 100mL titanic gel and calcined at 200°C was able to degradate 95.0% methyl orange (MO) in 5h under visible light. This study will pave a new and facile pathway for novel visible light driven photocatalysts based on TiO₂ modified by agricultural biomass waste.

Hierarchically porous structure, mechanical strength and cell biological behaviors of calcium phosphate composite scaffolds prepared by combination of extrusion and porogen burnout technique and enhanced by gelatin

In this study, hierarchically porous calcium phosphate scaffolds (HTCP) with unidirectional pores, transversely interconnected pores, and micropores were fabricated by the combination of extrusion and porogen burnout technique. Gelatin was incorporated into the HTCP scaffolds by vacuum-impregnation of gelatin solution and subsequent freeze-drying. The phase composition, microstructure, physical and cytobiological properties were analyzed. The results showed that the HTCP scaffolds were composed of β-tricalcium phosphate with minor hydroxyapatite. The HTCP scaffolds had unidirectional pores (~400μm), transversely interconnected pores (~130μm) and micropores (~1μm). The incorporation of gelatin significantly increased the compressive strength, toughness, and cell seeding of the HTCP scaffolds. The composite scaffolds showed excellent cytocompatibility. The hierarchically porous calcium phosphate composite scaffolds may have potential application prospects in bone tissue engineering.

High-activity chitosan/nano hydroxyapatite/zoledronic acid scaffolds for simultaneous tumor inhibition, bone repair and infection eradication

Implanted biomaterials combined tumor inhibition and bone repair property are urgently needed to address the huge bone destruction and the high local recurrence following primary surgery in bone tumor therapy. In this work, a high-activity chitosan/nano hydroxyapatite (CS/nHA) scaffold containing zoledronic acid (CS/nHA/Zol) was prepared with a facile method. The prepared CS/nHA/Zol scaffolds exhibited excellent tumor inhibition property towards giant cell tumor of bone (GCT) in vitro through inducing cells apoptosis by up-regulating pro-apoptosis genes expression and reducing the osteoclastic activity of tumor cells by down-regulating osteoclastic genes. Meanwhile, the prepared scaffolds possessed well biocompatibility and osteoinductivity as compared to pure CS/nHA scaffolds. Furthermore, the prepared scaffolds also presented outstanding antibacterial activity against clinical pathogenic S. aureus and E. coli. These overall findings successfully demonstrated the prepared CS/nHA/Zol scaffolds had a multifunction of tumor therapy, bone repair, and antibacterium, which provides a new approach possessed promising advantages in bone tumor therapy.

808nm light triggered black TiO2 nanoparticles for killing of bladder cancer cells

The black TiO₂ nanoparticles are synthesized via a facile calcination method combined with an in-situ controllable solid-state reaction approach. The results indicate that the photocatalyst with a narrow band gap of ~2.32 eV extends the photoresponse to visible light and near infrared region. And thus more reactive oxygen species can be obtained to induce the cell-killing under 808 nm light triggering. The as-obtained black TiO₂ nanoparticles exhibiting low toxicity, good biocompatibility and high anticancer effect in vitro, is demonstrated as efficient photosensitizers for phototherapy to kill the bladder cancer cells. These findings suggest that the facile synthetic black TiO₂ nanomaterials will have broad application in biomedicine.

Synthesis of silk fibroin-g-PAA composite using H2O2-HRP and characterization of the in situ biomimetic mineralization behavior

Silk fibroin (SF) as a bioactive protein can offer growth substrates for hydroxyapatite (HAp) deposition. In the current work, graft copolymerization of acrylic acid (AA) onto fibroin chains was carried out using hydrogen peroxide-horseradish peroxidase (H₂O₂-HRP) catalytic system, SF-g-polyacrylic acid (PAA) membranes was prepared subsequently, followed by in situ biomimetic mineralization in the Ca/P solutions, aiming at promoting the deposition of HAp and endowing the fibroin-based biocomposite with enhanced bioactivity. Meanwhile, p-hydroxyphenylacetamide (PHAD) and methyl acrylate (MA), as the model compounds of tyrosine residues in SF and vinyl monomer were used to disclose the mechanism of graft copolymerization. The data from FTIR and SEC chromatograms indicated that vinyl monomer was successfully graft copolymerized with SF during H₂O₂-HRP treatment. According to the results of XRD, SEM patterns and EDS-Mapping, mineral phases on the surfaces of SF-g-PAA membranes were detected after different cycles of biomimetic mineralization, and the mechanical property of SF-g-PAA/HAp membrane was noticeably improved. Cell viability and adhesion assays revealed that the composite of SF-g-PAA/HAp exhibited acceptable biocompatibility and outstanding adhesion property. The present work provides a novel method for preparation of the fibroin-based biomaterial for bone tissue engineering.

Functionalization of titanium dioxide nanotubes with biomolecules for biomedical applications

Titanium (Ti) and its alloys are extensively used in the manufacture of implants because they have biocompatibility. The production of a nanostructured surface can be achieved by means of titanium dioxide nanotubes (TNTs) which can have dimensions equivalent to the nanometric components of human bone, in addition to increasing the efficiency of such implants. The search is ongoing for ways to improve the performance of these TNTs in terms of their functionalization through coating these nanotubular matrices with biomolecules. The biocompatibility of the functionalized TNTs can be improved by promoting rapid osseointegration, by preventing the adhesion of bacteria on such surfaces and/or by promoting a more sustained local release of drugs that are loaded into such TNTs. In addition to the implants, these nanotubular matrices have been used in the manufacture of high-performance biosensors capable of immobilizing principally enzymes on their surfaces, which has possible use in disease diagnosis. The objective of this review is to show the main techniques of immobilization of biomolecules in TNTs, evidencing the most recent applications of bioactive molecules that have been functionalized in the nanotubular matrices for use in implants and biosensors. This surveillance also proposes a new class of biomolecules that can be used to functionalize these nanostructured surfaces, lectins.

Surface PEGylation of mesoporous silica materials via surface-initiated chain transfer free radical polymerization: Characterization and controlled drug release

As a new type of mesoporous silica materials with large pore diameter (pore size between 2 and 50nm) and high specific surface areas, SBA-15 has been widely explored for different applications especially in the biomedical fields. The surface modification of SBA-15 with functional polymers has demonstrated to be an effective way for improving its properties and performance. In this work, we reported the preparation of PEGylated SBA-15 polymer composites through surface-initiated chain transfer free radical polymerization for the first time. The thiol group was first introduced on SBA-15 via co-condensation with γ-mercaptopropyltrimethoxysilane (MPTS), that were utilized to initiate the chain transfer free radical polymerization using poly(ethylene glycol) methyl ether methacrylate (PEGMA) and itaconic acid (IA) as the monomers. The successful modification of SBA-15 with poly(PEGMA-co-IA) copolymers was evidenced by a series of characterization techniques, including ¹H NMR, FT-IR, TGA and XPS. The final SBA-15-SH- poly(PEGMA-co-IA) composites display well water dispersity and high loading capability towards cisplatin (CDDP) owing to the introduction of hydrophilic PEGMA and carboxyl groups. Furthermore, the CDDP could be released from SBA-15-SH-poly(PEGMA-co-IA)-CDDP complexes in a pH dependent behavior, suggesting the potential controlled drug delivery of SBA-15-SH-poly(PEGMA-co-IA). More importantly, the strategy should be also useful for fabrication of many other functional materials for biomedical applications owing to the advantages of SBA-15 and well monomer adoptability of chain transfer free radical polymerization.

Biocompatible β-SrHPO4 clusters with dandelion-like structure as an alternative drug carrier

Recent researches about calcium phosphate (CaP) biomaterials used as drug delivery systems are focusing on the better understanding of the microenvironment around the implant-host tissue interface, with the aim to provide a bone response in pathological ones. Towards the improvement of the osteogenic potential of CaP drug carriers, dandelion-like β-SrHPO₄ clusters (Φ10-20μm) has been prepared by a homogeneous precipitation method under the hydrolysis of carbamide. Adhesion, spreading, proliferation, osteogenic differentiation and mRNA expression of bone mesenchymal stem cells (BMSCs) mediated by β-SrHPO₄ clusters were investigated. Highly osteoconductive and biodegradable octacalcium phosphate with similar structure was employed as the control. By contrast, β-SrHPO₄ clusters exhibited remarkably better affinity, enhanced proliferation and osteogenic differentiation of BMSCs, providing a promising alternative bioactive bone substitute and drug carrier for tissue repair. With the unique dandelion-like microstructure, we believe that our as-prepared material will open up new avenues for applicability of CaP drug delivery systems in the near future.

Development of temozolomide coated nano zinc oxide for reversing the resistance of malignant glioma stem cells

Recently most of the researchers have turned their interest towards plant mediated synthesis of metal nanoparticles to avoid several environmental toxicants. In this manuscript, we have discussed the ecofriendly syntheses of zinc oxide nanoparticles (ZnO NPs) were achieved using Glycyrrhiza glabra (G. glabra) seed aqueous extract. The green synthesized ZnO NPs were characterized using analytical techniques like XRD, TEM, particle size histogram and Zeta potential. From the results, it was found that the green synthesized ZnO NPs were around 35nm in size with irregular spherical shape. The Zeta potential study of ZnO NPs was resulted to be high stabile with electronegative charge around -56.3mV. Further the G. glabra seed aqueous extract mediated synthesis of ZnO NPs were subjected to treat human glioblastoma cells with the help of temozolomide (TMZ) a commercially available drug by the method of MTT cell viability assay. The results stated that the ZnO NPs shows IC₅₀ value around 30μg/mL results significantly. The plausible mechanism behind the mortality rate was also discussed in this manuscript.

Microwave assisted synthesis of luminescent carbonaceous nanoparticles from silk fibroin for bioimaging

Bombyx mori silk as a natural protein based biopolymer with high nitrogen content, is abundant and sustainable because of its mass product all over the world per year. In this study, we developed a facile and fast microwave-assisted synthesis of luminescent carbonaceous nanoparticles using Bombyx mori silk fibroin and silk solution as the precursors. As a result, the obtained carbonaceous nanoparticles exhibit a photoluminescence quantum yield of ~20%, high stability, low cytotoxicity, high biocompatibility. Most importantly, we successfully demonstrated bioimaging using these luminescent carbonaceous nanoparticles with excitation dependent luminescence. In addition, the microwave-assisted hydrothermal method can be extended to convert other biomass into functional nanomaterials.