OBJECTIVE

This review article aims to determine the properties, uses, toxicity, and other side effects of crosslinking agents in tissue scaffolds when applied in vitro and in vivo.

A literature search was performed using the PubMed-NCBI (MEDLINE) database (https://pubmed.ncbi.nlm. nih.gov/) with keywords: crosslinking reagent, collagen, hydroxyapatite, and bone regeneration. GRADE criteria were used to assess the quality of evidence.

A total of six articles were included in the study. Improved mechanical properties of collagen-hydroxyapatite scaffolds with high porosity can be achieved by employing crosslinking methods, including physical dehydrothermal (DHT) treatment, chemical treatment with glutaraldehyde (GA), Microbial Transglutaminase (mTGase), 1‐ethyl‐3‐(3‐ dimethylaminopropyl) carbodiimide (EDAC), or a combination of both DHT and EDAC. Furthermore, the crosslinking of EDAC and DHT can lead to forming ester bonds between activated carboxyl groups and hydroxyl groups.

The combination of DHT and EDAC crosslinking can increase mechanical strength, make the pore size appropriate, make the scaffold more stable, and support cell adhesion so that new cells can grow, and the process of osteogenesis can run more optimally.

Haematitum and Limonitum are two iron-containing mineral medicines included in the 2020 edition of the Chinese Pharmacopoeia. They have similar main components and major differences in their property, flavor, channel tropism, and clinical uses. In this study, we investigated the surface properties, mineral composition, mineral dissociation, elemental composition, and iron state of Haematitum and Limonitum to explore their mineralogical differences. Scanning electron microscopy(SEM), specific surface and porosity analyzer, X-ray diffractometer(XRD), X-ray photoelectron spectrometer(XPS), and advanced mineral identification and characterization system(AMICS) were used to analyze the mineralogy of Haematitum and Limonitum. The results showed that Haematitum had an angular surface with granular attachments and a specific surface area of 17.04 m~2·g~(-1). In comparison, Limonitum had a smooth and flat surface with a bundled acicular crystal structure and a specific surface area of 46.29 m~2·g~(-1). Haematitum consists of 31 detectable minerals containing 18 elements, with the major element, iron(44.5% Fe~(2+) and 55.5% Fe~(3+)) distributed in 17 minerals, including hematite, iron oxide, knebelite, siderite, and magnesioferrite. Limonitum consists of 32 detectable minerals containing 17 elements, with the major element, iron(14.5% Fe~(2+) and 85.5% Fe~(3+)) distributed in 19 minerals, including limonite, iron oxide, chlorite, and knebelite. In summary, the elemental composition of Haematitum and Limonitum does not differ greatly, but there are large differences in the mineral composition and iron state. The large specific surface area and strong adsorption capacity of Limonitum may be one of the mechanisms of its anti-diarrheal action. The Fe_2O_3 and illite contained in Haematitum and Limonitum may be the key substances for their hemostasis effects. The mineralogical differences are expected to provide a reference for explaining the scientific connotation of mineral medicine and laying a material foundation for studying its mechanism of action.
Iron/analysis* ; Minerals/chemistry* ; Drugs, Chinese Herbal/chemistry* ; X-Ray Diffraction ; Microscopy, Electron, Scanning ; Photoelectron Spectroscopy

The phase changes and quantity-quality transfer of 17 batches of Ostreae Concha(Ostrea rivularis) during the raw material-calcined decoction pieces-standard decoction process were analyzed. The content of calcium carbonate(CaCO_3), the main component, was determined by chemical titration, and the extract yield and transfer rate were calculated. The CaCO_3 content in the raw material, calcined decoction pieces, and standard decoction was 94.39%-98.80%, 95.03%-99.22%, and 84.58%-90.47%, respectively. The process of raw material to calcined decoction pieces showed the yield range of 96.85% to 98.55% and the CaCO_3 transfer rate range of 96.92% to 99.27%. The process of calcined decoction pieces to standard decoction showed the extract yield range of 2.86% to 5.48% and the CaCO_3 transfer rate range of 2.59% to 5.13%. The results of X-ray fluorescence(XRF) assay showed that the raw material, calcined decoction pieces, and standard decoction mainly contained Ca, Na, Mg, Si, Br, Cl, Al, Fe, Cr, Mn, and K. The chemometric results showed an increase in the relative content of Cr, Fe, and Si from raw material to calcined decoction pieces and an increase in the relative content of Mg, Al, Br, K, Cl, and Na from calcined decoction pieces to standard decoction. X-ray diffraction(XRD) was employed to establish XRD characteristic patterns of the raw material, calcined decoction pieces, and standard decoction. The XRD results showed that the main phase of all three was calcite, and no transformation of crystalline form or generation of new phase was observed. Fourier transform infrared spectroscopy(FTIR) was employed to establish the FTIR characteristic spectra of the raw material, calcined decoction pieces, and standard decoction. The FTIR results showed that the raw material had internal vibrations of O-H, C-H, C=O, C-O, and CO■ groups. Due to the loss of organic matter components after calcination, no information about the vibrations of C-H, C=O, and C-O groups was observed in the spectra of calcined decoction pieces and standard decoction. In summary, this study elucidated the quantity-quality transfer and phase changes in the raw material-calcined decoction pieces-standard decoction process by determining the CaCO_3 content, calculating the extract yield and transfer rate, and comparing the element changes, FTIR characteristic spectra, and XRD characteristic pattern. The results were reasonable and reliable, laying a foundation for the subsequent process research and quality control of the formula granules of calcined Ostreae Concha(O. rivularis Gould), and providing ideas and methods for the quality control of the whole process of raw material-decoction pieces-standard decoction-formula granules of Ostreae Concha and other testacean traditional Chinese medicine.
Drugs, Chinese Herbal/isolation & purification* ; Calcium Carbonate/analysis* ; Quality Control

This study aims to investigate the polarized microscopic mineral phase characteristics, inorganic element content, and potential health risks associated with the intake of raw and calcined fossil mineral Chinese medicinal material Draconis Os. Microscopy was employed to observe the mineralogical characteristics of Draconis Os and compare the microscopic features and phase composition of raw and calcined Draconis Os under monochromatic and orthogonal polarized light. Inductively coupled plasma mass spectrometry(ICP-MS) was employed to determine the content of 30 inorganic elements. Health risk assessment was conducted by calculating the single pollution index(P_i), average daily intake of elements for adults(ADI), target hazard quotient(THQ), non-carcinogenic assessment method-hazard quotient(HQ), and the carcinogenic risk of elements(CR). The results indicated that under monochromatic polarized light, the Draconis Os powder sections exhibited light gray-brown to gray-brown irregular fragments, some with undulating textures that were slightly curved. Under crossed polarized light, they appeared dark gray, grayish-white, and yellowish-white. Clear apatite was visible in the ground sections of Draconis Os under crossed polarized light. P_i results indicated that Draconis Os samples were free from contamination and were of good quality. According to the maximum allowable limits of heavy metals stipulated in ISO Traditional Chinese Medicine: Determination of heavy metals in herbal medicines used in Traditional Chinese Medicine, ADI, THQ, HQ, and CR were taken as assessment indicators. Only the THQ value for As(arsenic) in raw Draconis Os was greater than 1, while the THQ values for other heavy metal elements in the Draconis Os samples were all less than 1. The study demonstrates that the primary mineral phase of raw and calcined Draconis Os is apatite, with some samples co-existing with calcite, which can serve as one of the means for quality control of Draconis Os. The elemental analysis results from ICP-MS provide scientific evidence for the safety assessment of Draconis Os, indicating that Draconis Os is safe in clinical application.
Drugs, Chinese Herbal/analysis* ; Risk Assessment ; Minerals/chemistry* ; Fossils ; Humans ; Drug Contamination ; Mass Spectrometry

OBJECTIVE: Recent studies have overturned the traditional concept of the lung as a "sterile organ" revealing that pulmonary microbiota dysbiosis and abnormal surfactant proteins (SPs) expression are involved in the progression of silicosis. This study aimed to investigate the relationship between abnormal SPs expression and dysbiosis of lung microbiota in silica-induced lung fibrosis, providing insights into mechanisms of silicosis. METHODS: Lung pathology, SPs expression, and microbiota composition were evaluated in silica-exposed mice. A mouse model of antibiotic-induced microbiota depletion was established, and alveolar structure and SPs expression were assessed. The roles of the lung microbiota and SPs in silicosis progression were further evaluated in mice with antibiotic-induced microbiota depletion, both with and without silica exposure. RESULTS: Silica exposure induced lung inflammation and fibrosis, along with increased expression of SP-A expression. Antibiotics (Abx)-induced microbiota depletion elevated SP-A and SP-D expression. Furthermore, silica exposure altered lung microbiota composition, enriching potentially pathogenic taxa. However, antibiotic-induced microbiota depletion prior to silica exposure reduced silica-mediated lung fibrosis and inflammation. CONCLUSION Lung microbiota is associated with silica-induced lung injury. Overproduction of SP-A and SP-D, induced by Abx-induced microbiota depletion, may enhance the resistance of mouse lung tissue to silica-induced injury.
Animals ; Silicosis/prevention & control* ; Lung/metabolism* ; Mice ; Anti-Bacterial Agents/pharmacology* ; Microbiota/drug effects* ; Silicon Dioxide/toxicity* ; Mice, Inbred C57BL ; Male ; Pulmonary Surfactant-Associated Proteins/genetics*

OBJECTIVES: This study aimed to compare the osteogenic performance differences of titanium surface coatings modified by dopamine or silanized graphene oxide, and to provide a more suitable modification scheme for titanium surface graphene oxide coatings. METHODS: Titanium was subjected to alkali-heat treatment and then modified with dopamine and silanization, respectively, followed by coating with graphene oxide. Control and experimental groups were designed as follows: pure titanium (Ti) group; titanium after alkali-heat treatment (Ti-NaOH) group; titanium after alkali-heat treatment and silanization modification (Ti-APTES) group; titanium after alkali-heat treatment and dopamine modification (Ti-DOPA) group; titanium with silanization-modified surface decorated with graphene oxide (Ti-APTES/GO) group; titanium with dopamine-modified surface decorated with graphene oxide (Ti-DOPA/GO) group. The physical and chemical properties of the material surfaces were analyzed using scanning electron microscopy (SEM), contact angle goniometer, X-ray photoelectron spectroscopy (XPS), and Raman spectrometer. The proliferation and adhesion morphology of mouse embryonic osteoblast precursor cells MC3T3-E1 on the material surfaces were observed by cell viability detection and immunofluorescence staining followed by laser confocal microscopy. The effects on the osteogenic differentiation of MC3T3-E1 cells were studied by alkaline phosphatase (ALP) staining, alizarin red staining and quantification, and real-time quantitative polymerase chain reaction. RESULTS: After modification with graphene oxide coating, a thin-film-like structure was observed on the surface under SEM. The hydrophilicity of all experimental groups was improved, among which the Ti-DOPA/GO group had the best hydrophilicity. XPS and Raman spectroscopy analysis showed that the modified materials exhibited typical D and G peaks, and XPS revealed the presence of a large number of oxygen-containing functional groups on the surface. CCK8 assay showed that all groups of materials had no cytotoxicity, and the proliferation level of the Ti-APTES/GO group was higher than that of the Ti-DOPA/GO group. Under the laser confocal microscope, the cells in the Ti-DOPA/GO and Ti-APTES/GO groups spread more fully. The Ti-DOPA/GO and Ti-APTES/GO groups had the deepest ALP staining, and the Ti-APTES/GO group had the most alizarin red-stained mineralized nodules and the highest quantitative result of alizarin red staining. In the Ti-DOPA/GO and Ti-APTES/GO groups, the expression of the early osteogenic-related gene RUNX2 reached a relatively high level, while in the expression of the late osteogenic-related genes OPN and OCN, the Ti-APTES/GO group performed better than the Ti-DOPA/GO group. CONCLUSIONS Ti-APTES/GO significantly outperformed Ti-DOPA/GO in promoting the adhesion, proliferation, and in vitro osteogenic differentiation of MC3T3-E1 cells.
Titanium/chemistry* ; Graphite/chemistry* ; Dopamine/chemistry* ; Animals ; Mice ; Osteogenesis ; Osteoblasts/cytology* ; Surface Properties ; Cell Proliferation ; Silanes/chemistry* ; Cell Adhesion ; Coated Materials, Biocompatible/chemistry* ; Cell Differentiation ; Alkaline Phosphatase/metabolism* ; Microscopy, Electron, Scanning

OBJECTIVES: To compare the clinical effects of concentrated growth factor (CGF) membrane and Bio-Gide ^® collagen membrane, combined with Bio-Oss ^® sticky bone respectively in alveolar ridge preservation (ARP) of maxillary anterior teeth. METHODS: Thirty patients who needed alveolar ridge preservation after maxillary anterior tooth extraction were selected and randomly assigned to the Bio-Gide group and the CGF group. In both groups, the extraction sockets were tightly filled with the Bio-Oss^® sticky bone. In the Bio-Gide group used Bio-Gide^® collagen membrane to cover the upper edge of the Bio-Oss^® sticky bone and closed the wound. The CGF group, the CGF membrane was covered on the upper edge of the Bio-Oss^® sticky bone and the wound was closed. The soft tissue wound healing status at 10 days after ARP, the changes in alveolar ridge height and width immediately after ARP and at 6 months after ARP, and the doctor-patient satisfaction at 6 months after ARP were compared and evaluated between the two groups. RESULTS: At 6 months after ARP, there was no statistically significant difference in the changes of alveolar bone width and height between the two groups (P>0.05). However, the CGF group showed better performance in soft tissue healing after ARP and doctor-patient satisfaction, and the differences were statistically significant (P<0.05). CONCLUSIONS Compared with the Bio-Gide^® collagen membrane, the combined application of CGF membrane and Bio-Oss^® sticky bone can lead to better soft tissue healing after ARP of maxillary anterior teeth and higher doctor-patient satisfaction, showing obvious advantages in ARP of maxillary anterior teeth.
Humans ; Maxilla/surgery* ; Tooth Extraction ; Alveolar Process/surgery* ; Membranes, Artificial ; Alveolar Ridge Augmentation/methods* ; Intercellular Signaling Peptides and Proteins/therapeutic use* ; Minerals/therapeutic use* ; Collagen ; Wound Healing ; Tooth Socket/surgery* ; Bone Substitutes/therapeutic use* ; Male ; Female ; Middle Aged ; Alveolar Bone Loss/prevention & control* ; Adult

Biosynthesized selenium nanoparticles (SeNPs) have attracted much attention because of their unique physical, chemical, and biological properties. The microbial reduction of selenium salts to SeNPs has great potential, while there is a lack of elite strains. In this study, we explored the reduction of Na₂SeO₃ by Streptomyces avermitilis into SeNPs. The colonies and hyphae of the strain and the synthesized SeNPs were characterized by optical microscopy, scanning electron microscopy (SEM), transmission electron microscope (TEM), energy dispersive spectrometry (EDS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). At the same time, the inhibitory activity of SeNPs on Fusarium oxysporum, the main pathogen causing root rot of Lycium barbarum, was studied. The results showed that S. avermitilis converted Na₂SeO₃ into SeNPs and tolerated 300 mmol/L Na₂SeO₃, demonstrating strong tolerance. S. avermitilis synthesized spherical SeNPs in the cytoplasm, and most of SeNPs had a diameter of about 100 nm and were released by hyphal fracture. The SeNPs synthesized by S. avermitilis were amorphous, and their surfaces were dominated by C and Se, with the existence of O, N and other elements. SeNPs had functional groups such as -OH, C=O, C-N, and C-H, which were closely related to the stability and biological activity of SeNPs. The SeNPs synthesized by S. avermitilis showcased significant inhibitory activity on F. oxysporum, and 25.0 μmol/mL SeNPs showcased the inhibition rate of 77.61% and EC₅₀ of 0.556 μmol/mL. In conclusion, S. avermitilis can tolerate high Na₂SeO₃ stress and mediate the synthesis of SeNPs. The synthesized SeNPs have good stability and strong inhibitory activity, demonstrating the potential application value in the preparation of SeNPs and the control of L. barbarum root rot.
Streptomyces/metabolism* ; Fusarium/drug effects* ; Lycium/microbiology* ; Selenium/metabolism* ; Nanoparticles/chemistry* ; Plant Diseases/microbiology* ; Metal Nanoparticles/chemistry* ; Antifungal Agents/pharmacology*

OBJECTIVE: To summarize the latest research progress of graphene and its derivatives (GDs) in bone repair. METHODS: The relevant research literature at home and abroad in recent years was extensively accessed. The properties of GDs in bone repair materials, including mechanical properties, electrical conductivity, and antibacterial properties, were systematically summarized, and the unique advantages of GDs in material preparation, functionalization, and application, as well as the contributions and challenges to bone tissue engineering, were discussed. RESULTS: The application of GDs in bone repair materials has broad prospects, and the functionalization and modification technology effectively improve the osteogenic activity and material properties of GDs. GDs can induce osteogenic differentiation of stem cells through specific signaling pathways and promote osteogenic activity through immunomodulatory mechanisms. In addition, the parameters of GDs have significant effects on the cytotoxicity and degradation behavior. CONCLUSION GDs has great potential in the field of bone repair because of its excellent physical and chemical properties and biological properties. However, the cytotoxicity, biodegradability, and functionalization strategies of GDs still need to be further studied in order to achieve a wider application in the field of bone tissue engineering.
Graphite/pharmacology* ; Tissue Engineering/methods* ; Humans ; Osteogenesis/drug effects* ; Biocompatible Materials/pharmacology* ; Bone Regeneration ; Tissue Scaffolds/chemistry* ; Cell Differentiation ; Bone and Bones ; Bone Substitutes/chemistry* ; Animals

OBJECTIVE: To review the research progress and challenges of poly (L-lactic acid) (PLLA) membrane in preventing tendon adhesion. METHODS: The relevant literature at home and abroad in recent years was extensively searched, covering the mechanism of tendon adhesion formation, the adaptation challenge and balancing strategy of PLLA, the physicochemical modification of PLLA anti-adhesion membrane and its application in tendon anti-adhesion. In this paper, the research progress and modification strategies of PLLA membranes were systematically reviewed from the three dimensions of tissue adaptation, mechanical adaptation, and degradation adaptation. RESULTS: The three-dimensional adaptation of PLLA membrane is optimized by combining materials (such as hydroxyapatite, polycaprolactone), structural design (multilayer/gradient membrane), and drug loading (anti-inflammatory drug). The balance between anti-adhesion and pro-healing is achieved, the mechanical adaptation significantly improve, and degradation is achieved (targeting the degradation cycle to 2-4 weeks to cover the tendon repair period). CONCLUSION In the future, it is necessary to identify the optimal balance point of three-dimensional fitness, unify the evaluation criteria and solve the degradation side effects through the co-design of physicochemical modification and drug loading system to break through the bottleneck of clinical translation.
Tissue Adhesions/prevention & control* ; Polyesters/chemistry* ; Humans ; Biocompatible Materials/chemistry* ; Tendons/surgery* ; Membranes, Artificial ; Tendon Injuries/surgery* ; Wound Healing ; Animals ; Durapatite/chemistry*