silicon and Bone-Neoplasms

In a study on 25 patients with verified benign bone tumors, bioactive glass (BG) and autogenous bone (AB) were used as bone-graft substitutes. The patients were randomized into two groups according to the filling material. Blood samples were taken both preoperatively, at 2 weeks, and 3, 8, 12, 24, and 36 months postoperatively, for evaluation of silicon concentration in blood. In the determination, direct current plasma atomic emission spectroscopy was used. No significant difference in blood silicon concentration between the BG group or the AB group could statistically be observed (p = 0.5400), and neither did the size of the bone tumor (p = 0.4259) nor the follow-up time affect the results (p = 0.2094). Concentration of osteocalcin in blood was significantly higher for large cysts (p < 0.0001). The filler material (BG or AB) did not affect the osteocalcin concentration level in blood.

Topics: Bone Neoplasms; Bone Substitutes; Bone Transplantation; Glass; Humans; Longitudinal Studies; Materials Testing; Osteocalcin; Silicon; Stem Cell Niche; Transplantation, Autologous

Currently, the treatment strategy for bone metastasis is mainly to inhibit the growth of tumor cells and the activity of osteoclasts, while ignoring the influence of the tumor stromal microenvironment (TSM) on the progression of bone metastasis. Herein, a dual-target liquid metal (LM)-based drug delivery system (DDS) with favorable photothermal performance is designed to spatially program the delivery of multiple therapeutic agents to enhance the treatment of bone metastasis through TSM remodeling. Briefly, mesoporous silicon-coated LM is integrated into zeolitic imidazolate framework-8 (ZIF-8) with both bone-seeking and tumor-targeting capacities. Curcumin (Cur), a tumor microenvironment modulator, is encapsulated into ZIF-8, and doxorubicin (DOX) is enclosed inside mesoporous silicon. Specific accumulation of the LM-based DDS in bone metastases first relieves the tumor stroma by releasing Cur in response to the acidic tumor microenvironment and then releases DOX deep into the tumor under near-infrared light irradiation. The combined strategy of the LM-based DDS and mild photothermal therapy has been shown to effectively restrain cross-talk between osteoclasts and tumor cells by inhibiting the secretion of transforming growth factor-β, degrading extracellular matrix components, and increasing infiltration of CD4

Topics: Bone Neoplasms; Breast Neoplasms; CD8-Positive T-Lymphocytes; Cell Line, Tumor; Doxorubicin; Female; Humans; Hyperthermia, Induced; Metal Nanoparticles; Nanoparticles; Phototherapy; Photothermal Therapy; Silicon; Tumor Microenvironment

Osteosarcoma is a malignant tumor with relatively high mortality rates in children and adolescents. While nanoparticles have been widely used in assisting the diagnosis and treatment of cancers, the biodistributions of nanoparticles in osteosarcoma models have not been well studied. Herein, we synthesize biocompatible and highly photoluminescent silicon quantum dot nanoparticles (SiQDNPs) and investigate their biodistributions in osteosarcoma mouse models after intravenous and intratumoral injections by fluorescence imaging. The bovine serum albumin (BSA)-coated and poly(ethylene glycol) (PEG)-conjugated SiQDNPs, when dispersed in phosphate-buffered saline (PBS), can emit red photoluminescence with the photoluminescence quantum yield more than 30% and have very low

Topics: Adolescent; Animals; Bone Neoplasms; Child; Humans; Indocyanine Green; Injections, Intralesional; Mice; Nanoparticles; Osteosarcoma; Polyethylene Glycols; Quantum Dots; Silicon; Tissue Distribution

Collective cell migration, in which cells migrate as a group, is fundamental in many biological and pathological processes. There is increasing interest in studying the collective cell migration in high throughput. Cell scratching, insertion blocker, and gel-dissolving techniques are some methodologies used previously. However, these methods have the drawbacks of cell damage, substrate surface alteration, limitation in medium exchange, and solvent interference. The superhydrophobic surface, on which the water contact angle is greater than 150 degrees, has been recently utilized to generate patterned arrays. Independent cell culture areas can be generated on a substrate that functions the same as a conventional multiple well plate. However, so far there has been no report on superhydrophobic patterning for the study of cell migration. In this study, we report on the successful development of a robotically patterned superhydrophobic array for studying collective cell migration in high throughput. The array was developed on a rectangular single-well cell culture plate consisting of hydrophilic flat microwells separated by the superhydrophobic surface. The manufacturing process is robotic and includes patterning discrete protective masks to the substrate using 3D printing, robotic spray coating of silica nanoparticles, robotic mask removal, robotic mini silicone blocker patterning, automatic cell seeding, and liquid handling. Compared with a standard 96-well plate, our system increases the throughput by 2.25-fold and generates a cell-free area in each well non-destructively. Our system also demonstrates higher efficiency than conventional way of liquid handling using microwell plates, and shorter processing time than manual operating in migration assays. The superhydrophobic surface had no negative impact on cell viability. Using our system, we studied the collective migration of human umbilical vein endothelial cells and cancer cells using assays of endpoint quantification, dynamic cell tracking, and migration quantification following varied drug treatments. This system provides a versatile platform to study collective cell migration in high throughput for a broad range of applications.

Topics: Bone Neoplasms; Cell Movement; Cell Survival; Cell Tracking; Cells, Cultured; Human Umbilical Vein Endothelial Cells; Humans; Hydrophobic and Hydrophilic Interactions; Nanotechnology; Osteosarcoma; Printing, Three-Dimensional; Robotics; Silicon

Effective treatment of cancer metastasis to the bone relies on bone marrow drug accumulation. The surface proteins in the bone marrow vascular endothelium provide docking sites for targeted drug delivery. We have developed a thioaptamer that specifically binds to E-selectin that is overexpressed in the vasculature of tumor and inflammatory tissues. In this study, we tested targeted delivery of therapeutic siRNA loaded in the E-selectin thioaptamer-conjugated multistage vector (ESTA-MSV) drug carrier to bone marrow for the treatment of breast cancer bone metastasis. We evaluated tumor type- and tumor growth stage-dependent targeting in mice bearing metastatic breast cancer in the bone, and carried out studies to identify factors that determine targeting efficiency. In a subsequent study, we delivered siRNA to knock down expression of the human STAT3 gene in murine xenograft models of human MDA-MB-231 breast tumor, and assessed therapeutic efficacy. Our studies revealed that the CD31(+)E-selectin(+) population accounted for 20.8%, 26.4% and 29.9% of total endothelial cells respectively inside the femur of mice bearing early, middle and late stage metastatic MDA-MB-231 tumors. In comparison, the double positive cells remained at a basal level in mice with early stage MCF-7 tumors, and jumped to 23.9% and 28.2% when tumor growth progressed to middle and late stages. Accumulation of ESTA-MSV inside the bone marrow correlated with the E-selectin expression pattern. There was up to 5-fold enrichment of the targeted MSV in the bone marrow of mice bearing early or late stage MDA-MB-231 tumors and of mice with late stage, but not early stage, MCF-7 tumors. Targeted delivery of STAT3 siRNA in ESTA-MSV resulted in knockdown of STAT3 expression in 48.7% of cancer cells inside the bone marrow. Weekly systemic administration of ESTA-MSV/STAT3 siRNA significantly extended survival of mice with MDA-MB-231 bone metastasis. In conclusion, targeting the overexpressed E-selectin provides an effective approach for tissue-specific drug delivery to the bone marrow. Tumor growth in the bone can be effectively inhibited by blockage of the STAT3 signaling.

Topics: Animals; Aptamers, Nucleotide; Bone Marrow; Bone Neoplasms; Breast Neoplasms; Cell Line, Tumor; Drug Carriers; E-Selectin; Endothelial Cells; Endothelium; Female; Femur; Humans; MCF-7 Cells; Mice; Mice, Nude; RNA, Small Interfering; Silicon; STAT3 Transcription Factor

A 71-year-old man who had undergone chest wall resection and reconstruction with a Dacron mesh silicone prosthesis for chondrosarcoma 23 years previously presented with a chest wall hematoma. Since the hematoma was found to increase in size over time, we performed an operation to achieve hemostasis. Operative findings showed that the prosthesis had separated into three sheets.

Topics: Aged; Anticoagulants; Bone Neoplasms; Chondrosarcoma; Hematoma; Hemorrhage; Hemostatic Techniques; Humans; Male; Plastic Surgery Procedures; Polyethylene Terephthalates; Prosthesis Design; Prosthesis Failure; Reoperation; Silicon; Surgical Mesh; Thoracic Neoplasms; Thoracic Surgical Procedures; Thoracic Wall; Time Factors; Tomography, X-Ray Computed

The molecular level damage to DNA is important due to DNA's susceptibility to free radical attacks and crucial roles in maintaining cell functions. Although a panel of techniques can be used to detect DNA damages, most of them are limited due to low sensitivity, low throughput, incompatibility for automated data analysis, and labor-intensive operations. We have developed a cell array based DNA damage assay in which mammalian cells are attached on an array of microfabricated patterns through electrostatic interactions. After trapping patterned cells inside gels, damaged DNA fragment can diffuse out of the nucleus and form a halo around each cell inside gels. The halo array can be observed fluorescently after labeling DNA with ethidium bromide. DNA damages can be determined sensitively at the single cell level, accurately due to the symmetric shape of the halo, and automatically due to the spatial registry of each cell and the nonoverlapping halos surrounding cells. The HaloChip can be used to detect DNA damages caused by chemicals and ultraviolet and X-ray irradiations with high efficiency. A major advantage of HaloChip is the ability to increase throughout by spatially encoding multiple dosing conditions on the same chip. Most importantly, the method can be used to measure variations in response to DNA damaging agents within the same cell population. Compared with halo assay or comet assay alone, this method allows automated analysis of a million cells without an overlapping issue. Compared with the microwell array based comet assay, this method can selectively capture and analyze cells, and the results can be easily analyzed to provide precise information on DNA damage. This method can be used in a broad range of clinical, epidemiological, and experimental settings.

Topics: Biological Assay; Bone Neoplasms; Cell Nucleus; Comet Assay; DNA Damage; DNA Repair; Fluorescence; HeLa Cells; Humans; Osteosarcoma; Silicon; Tissue Array Analysis; Tumor Cells, Cultured; X-Rays

In this paper, a calcium zinc iron silicon oxide composite (CZIS) was prepared using the sol-gel method. X-ray diffraction (XRD) was then employed to test the CZIS composite. The results from the test showed that the CZIS had three prominent crystalline phases: Ca(2)Fe(1.7)Zn(0.15)Si(0.15)O(5), Ca(2)SiO(4), and ZnFe(2)O(4). Calorimetric measurements were then performed using a magnetic induction furnace. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analysis were conducted to confirm the growth of a precipitated hydroxyapatite phase after immersion in simulated body fluid (SBF). Cell culture experiments were also carried out, showing that the CZIS composite more visibly promoted osteoblast proliferation than ZnFe(2)O(4) glass ceramic and HA, and osteoblasts adhered and spread well on the surfaces of composite samples.

Topics: Animals; Body Fluids; Bone Diseases; Bone Neoplasms; Calcium; Calorimetry; Cell Survival; Durapatite; Humans; Hyperthermia, Induced; Iron; Magnetics; Osteoblasts; Oxides; Particle Size; Rats; Rats, Sprague-Dawley; Silicon; X-Ray Diffraction; Zinc