Immune-Enhancing Effect of Sargassum horneri on Cyclophosphamide-Induced Immunosuppression in BALB/c Mice and Primary Cultured Splenocytes.

Sargassum horneri (SH) is a seaweed that has several features that benefit health. In this study, we investigated the immune-enhancing effect of SH, focusing on the role of spleen-mediated immune functions. Chromatographic analysis of SH identified six types of monosaccharide contents, including mannose, rhamnose glucose, galactose xylose and fucose. SH increased cell proliferation of primary cultured naïve splenocytes treated with or without cyclophosphamide (CPA), an immunosuppression agent. SH also reversed the CPA-induced decrease in Th1 cytokines. In vivo investigation revealed that SH administration can increase the tissue weight of major immune organs, such as the spleen and thymus. A similar effect was observed in CPA-injected immunosuppressed BALB/c mice. SH treatment increased the weight of the spleen and thymus, blood immune cell count and Th1 cytokine expression. Additionally, the YAC-1-targeting activities of natural killer cells, which are important in innate immunity, were upregulated upon SH treatment. Overall, our study demonstrates the immune-enhancing effect of SH, suggesting its potential as a medicinal or therapeutic agent for pathologic conditions involving immunosuppression.

Increased external rotation of the osteoarthritic knee joint according to the genu varum deformity.

PURPOSE: To evaluate the rotational profile of the lower extremity using computed tomography (CT) in accordance with the degree of varus deformity in medial condyle-affected knee joint osteoarthritis (OA). METHODS: This retrospective study included 1036 patients (872 lower extremities) with end-stage knee OA. The coronal alignment of the lower extremity was measured using standing anteroposterior radiography. The CT parameters of femoral anteversion and tibial torsion were assessed in relation to the knee joint. The axes were the femoral neck axis; the distal femoral axis, which was composed of the anterior trochlear axis, the clinical transepicondylar axis, and the posterior condylar axis; the axis of the proximal tibial condyles; and the bimalleolar axis. RESULTS: There was a tendency for increased external rotation of the knee joint parameters in relation to the hip and ankle joints as varus deformity of the lower extremity increased. The relative external rotational deformity of the knee joint in relation to the hip joint had a positive value with a good correlation. The relative external rotational deformity of the knee joint in relation to the ankle joint also demonstrated a positive value with a good correlation. CONCLUSION: The distal femur and proximal tibia (knee joint) tended to rotate externally in relation to the hip and ankle joint, respectively, as the degree of varus deformity increased. This study identified the relationship between lower extremity varus deformity and rotational deformity of knee joints with OA. LEVEL OF EVIDENCE: III.

Lifetime and diffusion distance of singlet oxygen in air under everyday atmospheric conditions.

Singlet oxygen is a toxic chemical but powerful oxidant, exploited in many chemical and biological applications. However, the lifetime of singlet oxygen in air under atmospheric conditions is yet to be known. This has limited safe usage of singlet oxygen in air, despite being a strong antimicrobial agent with the unique property of relaxing to breathable oxygen after serving its purpose. Here, we solve this long-standing problem by combining experimental and theoretical research efforts; we generate singlet oxygen using a photosensitizer at a local source and monitor the time-dependent extent of singlet oxygen reaction with probe molecules at a detector, precisely controlling the detector distance from the source. To explain our experimental results, we employ a theoretical model that fully accounts for singlet oxygen diffusion, radiative and nonradiative relaxations, and the bimolecular reaction with probe molecules at the detector. For all cases investigated, our model, with only two adjustable parameters, provides an excellent quantitative explanation of the experiment. From this analysis, we extract the lifetime of singlet oxygen in the air to be 2.80 s at 23 °C under 1 atm, during which time singlet oxygen diffuses about 0.992 cm. The correctness of this estimation is confirmed by a simple mean-first-passage time analysis of the maximum distance singlet oxygen can reach from the source. We also confirm the sterilization effects of singlet oxygen for distances up to 0.6-0.8 cm, depending on the bacteria strain in question, between the bacteria and the singlet oxygen source.

Successful arthroscopic treatment of refractory and complicated popliteal cyst associated with rheumatoid arthritis in combination with osteoarthritis: case series and literature review.

Although popliteal cysts are most frequently identified in patients with osteoarthritis (OA), they may occur in patients with rheumatoid arthritis (RA), in which serious complicated cases such as cyst rupture can be developed. The objective of this study was to report four patients with RA (six knees) in combination with OA with a brief review of literature of previous similar published cases. This is a retrospective review of case records of patients with refractory and/or complicated popliteal cysts, who have successfully treated with arthroscopic intervention. We suggest that arthroscopic interventions such as radical debridement, synovectomy, biomechanical valve excision, and/or cystectomy should be considered in patients with refractory and complicated popliteal cysts associated with RA or RA in combination with OA.

Effects of Preoperative Virtual Reality Magnetic Resonance Imaging on Preoperative Anxiety in Patients Undergoing Arthroscopic Knee Surgery: A Randomized Controlled Study.

PURPOSE: To assess the effect of a preoperative virtual reality (VR) experience of 3-dimensional (3D) reconstructed magnetic resonance images (MRIs) on anxiety reduction in patients undergoing arthroscopic knee surgery. METHODS: Patients in the VR group watched a 3D model of their own MRI through a VR headset describing the anatomy of the knee as well as their own lesion of interest for an arthroscopic procedure. Patients in the non-VR (NR) group received standard preoperative information about their MRI. The primary outcome for analysis was the Amsterdam Preoperative Anxiety and Information Scale score to measure level of anxiety and the need for information in patients undergoing arthroscopic knee surgery. Secondary outcomes were rated with visual analog scale (VAS) scores measuring patient pain, preparedness, satisfaction, and stress. RESULTS: Regarding the Amsterdam Preoperative Anxiety and Information Scale score, the sum S (surgery-related anxiety) and sum C (combined anxiety component) subscales showed significantly better outcomes in the VR group (median [interquartile range] for sum S = 2.0 [2.0-4.0], median [quartile 1-quartile 3] sum C = 4.0 [4.0-8.5]) than in the NR group (median [interquartile range] for sum S = 4.9 [3.0-5.0], median [quartile 1-quartile 3] sum C = 8.0 [5.3-9.8]) (P = .014 and P = .005, respectively). Regarding VAS scores, preoperative measures showed significantly better outcomes in satisfaction among VR group patients (95 [90.0-100.0]) in comparison to NR group patients (85 [70.0-96.0]) (P = .010). For postoperative VAS measures, the VR group (satisfaction score = 95 [90.0-100.0], stress score = 15 [2.5-37.5]) showed significantly better outcomes in satisfaction and stress in comparison to the NR group (satisfaction score = 85 [70.0-97.5], stress score = 30 [30.0-50.0]). CONCLUSIONS: Application of preoperative VR experience of 3D reconstructed knee MRIs in patients undergoing arthroscopic knee surgery reduces anxiety around surgical encounters. The VR patient group was more satisfied overall and less stressed postoperatively. However, perioperative pain and preparedness were not affected by VR exposure. LEVEL OF EVIDENCE: Level I, randomized controlled trial.

Identification and characterization of human bone-derived cells.

This study was designed to identify and characterize primary bone-derived cells (BdCs) and investigate the potential role of osteoblast differentiation. Primary BdCs were isolated from surgical bone for comparative analysis with mesenchymal stem cells (MSCs) and fetal osteoblasts (FOBs) and for potential differentiation to mature osteoblasts. Using three different cells, we successfully cultivated human osteoblast differentiation and activity which were evaluated using microarray and biochemical methods. BdCs are more correlated to MSCs in bioinformatics result and similar with FOBs in gene expression. In particular, Osterix, osteoprogenitor marker, was high expressed in BdCs, while the expression in MSCs and FOBs were very low. Furthermore, BdCs exhibited a marked alkaline phosphatase (ALP) expression, early stage of osteogenic marker, and retained osteogenic properties and physiological changes into maturation as in FOBs. BdCs also showed an increase in bone morphogenic protein 2 (BMP2), osteopontin (OPN), and osteocalcin (OCN) mRNA expressions during differentiation. This study suggests that BdCs may be osteoprogenitor cells or undifferentiated preosteoblasts with strong capacity to differentiate toward mature osteoblasts.

Inferior outcome of revision of unicompartmental knee arthroplasty to total knee arthroplasty compared with primary total knee arthroplasty: systematic review and meta-analysis.

PURPOSE: The purpose of this study was to compare the revision of unicompartmental knee arthroplasty (UKA) to total knee arthroplasty (TKA) with primary TKA through a review of previously published studies. The hypothesis was that the revised UKA group would need additional operative procedures, including the use of stems and augments, resulting in poorer clinical outcomes than those of the primary TKA group. METHODS: A literature search of online register databases was performed to identify clinical trials that compared revised UKA to TKA with primary TKA. An electronic literature search was performed using the Medline, Embase, Cochrane Library, Web of Science, and Scopus databases. No language or date restrictions were applied. RESULTS: A total of 2034 articles were identified from a keyword search, of which 11 studies were determined as eligible. They were all retrospective comparative studies. The revised UKA to TKA group had longer operation times resulting from additional procedures such as bone grafting and use of stems and augments, higher reoperation rates, and worse postoperative clinical outcomes based on the Western Ontario and McMaster Universities Osteoarthritis Index and Oxford Knee Score than the primary TKA group, with the differences being statistically significant. CONCLUSION: UKA should not be considered an alternative procedure to TKA. LEVEL OF EVIDENCE: Therapeutic Level III.

A higher association of medial collateral ligament injury of the knee in pronation injuries of the ankle.

INTRODUCTION: To evaluate the prevalence of medial collateral ligament (MCL) injury of the knee among ankle-fracture patients and to determine the risk factors associated with MCL injury in this patient group. MATERIALS AND METHODS: 303 patients (303 affected ankles) who underwent surgical treatment for an ankle fracture were assessed. Supination versus pronation injury, Danis-Weber classification, age, sex, body mass index (BMI), limb dominance, and mechanism of injury were reviewed to identify factors related to MCL injury. RESULTS: Prevalence of MCL injury of the knee among the total number of patients with an ankle fracture was 3.96% (12 out of 303 injuries). Multivariable logistic and linear regression analysis with adjustment of possible confounding factors confirmed that female sex and pronation injury were associated significantly (p < 0.05) with MCL injury. CONCLUSIONS: The prevalence of MCL injury among females and the pronation type of ankle injury was 8.19% (10 out of 122 females) and 10.75% (10 out of 93 pronation injuries), respectively. More careful physical examination of the knee joint is strongly recommended in patients with ankle fractures, especially if the patient is female or the ankle-fracture pattern corresponds to the pronation type of injury.

ST8SIA4-Dependent Polysialylation is Part of a Developmental Program Required for Germ Layer Formation from Human Pluripotent Stem Cells.

Polysialic acid (PSA) is a carbohydrate polymer of repeating α-2,8 sialic acid residues that decorates multiple targets, including neural cell adhesion molecule (NCAM). PST and STX encode the two enzymes responsible for PSA modification of target proteins in mammalian cells, but despite widespread polysialylation in embryonic development, the majority of studies have focused strictly on the role of PSA in neurogenesis. Using human pluripotent stem cells (hPSCs), we have revisited the developmental role of PST and STX and show that early progenitors of the three embryonic germ layers are polysialylated on their cell surface. Changes in polysialylation can be attributed to lineage-specific expression of polysialyltransferase genes; PST is elevated in endoderm and mesoderm, while STX is elevated in ectoderm. In hPSCs, PST and STX genes are epigenetically marked by overlapping domains of H3K27 and H3K4 trimethylation, indicating that they are held in a "developmentally-primed" state. Activation of PST transcription during early mesendoderm differentiation is under control of the T-Goosecoid transcription factor network, a key regulatory axis required for early cell fate decisions in the vertebrate embryo. This establishes polysialyltransferase genes as part of a developmental program associated with germ layer establishment. Finally, we show by shRNA knockdown and CRISPR-Cas9 genome editing that PST-dependent cell surface polysialylation is essential for endoderm specification. This is the first report to demonstrate a role for a glycosyltransferase in hPSC lineage specification. Stem Cells 2016;34:1742-1752.

Highly efficient Blue-Emitting CdSe-derived Core/Shell Gradient Alloy Quantum Dots with Improved Photoluminescent Quantum Yield and Enhanced Photostability.

Highly efficient blue-emitting CdSe-derived core/shell gradient alloy quantum dots (CSGA QDs) with photoluminescence quantum yield (PL QY) of ca. 90% have been synthesized through a facile "one-pot" approach. CdSe nuclei are initially formed as core and gradient alloy shells such as CdSexS1-x/ZnSeyS1-y simultaneously encapsulate the preformed CdSe core in an energy-gradient fashion eventually followed by coating with ZnS shells due to the faster precursor reaction kinetics of Cd and Se compared to analog of Zn and S. During the formation of core/shell structure, red-shifting of absorption/emission peaks followed by blue-shifting of analogues were observed due to the intradiffusion of sulfur anion to CdSe luminescent center. In this gradient architecture, interfacial lattice strain can be effectively alleviated, and thus high PL QY (ca. 90%) and enhanced photochemical stability can be achieved. The synthesized blue-emitting gradient alloy QDs with superior optical properties tunable in the range of 450-490 nm can be used for highly efficient blue-emitters and potentially applicable for the fabrication of white-light LEDs.

Surface Coating of Gradient Alloy Quantum Dots with Oxide Layer in White-Light-Emitting Diodes for Display Backlights.

Recently, quantum dots (QDs) have been successfully developed as efficient color converters for light-emitting diodes (LEDs) display due to excellent optical properties of QDs. Herein, we demonstrate a new approach to form metal oxide layers (or metal oxide coating) on the exterior surface of gradient alloy QDs (the most advanced chemical architecture QDs developed thus far wherein the lattice parameter from the core to shell is changing in a gradient fashion) in order to improve the photochemical stability and photoluminescence efficiency. The resulting CdO-treated QDs are incorporated into polymer matrix films to fabricate a backlight unit as a part of display panel wherein CdO-treated gradient alloy QDs are utilized as color converters upon the blue-LED excitation. The fabricated 9.7 in. iPad 2 tablet liquid crystal display panel exhibited an excellent uniformity in terms of CIE chromaticity, luminance, and bright variation and superb durability test results (maintenance of ca. 110% brightness compared to initial value even after 3 weeks of operation).

Germinated Waxy Black Rice Ameliorates Hyperglycemia and Dyslipidemia in Streptozotocin-Induced Diabetic Rats.

This study aimed to examine the anti-diabetic effect of germinated waxy black rice (GWBR) using streptozotocin (STZ)-induced diabetic rats. In the diabetic rats, GWBR supplementation for 8 weeks reduced plasma blood glucose concentrations, improved glucose clearance and prevented diabetes-induced weight loss. Rats with STZ-induced diabetes who received GWBR supplementation exhibited decreased expression of sodium-dependent glucose transporter 1 (SGLT1) and glucose transporter (GLUT) 2 genes and proteins in the small intestine via decreases in hepatocyte nuclear factor (HNF)-1α, HNF-1ß, and HNF-4α, transcriptional factors that are involved in the regulation of SGLT1 and GLUT2, compared with the rats with STZ-induced diabetes that did not receive GWBR supplements. GWBR supplementation also enhanced the expression of GLUT4 and the genes and proteins involved in GLUT4 translocation, such as insulin receptor (IR) and insulin receptor substrate 1 (IRS1), and increased the phosphorylation of phosphoinositide 3-kinase (PI3K) and protein kinase B (PKB, Akt) proteins in skeletal muscle. GWBR further increased glycogen synthase (GS) 1 by decreasing glycogen synthase kinase (GSK)-3ß in skeletal muscle. Interestingly, GWBR recovered STZ-impaired pancreatic ß-cells, resulting in increased insulin synthesis and secretion. In addition, GWBR reduced serum triglyceride, total cholesterol, low-density lipoprotein cholesterol, aspartate transferase and alanine transferase concentrations and increased high-density lipoprotein cholesterol concentrations. Taken together, these findings suggest that GWBR could be a candidate for improving the diabetic condition by regulating glucose uptake in the intestine and muscle and regulating the secretion of insulin from the pancreas.

Safety and efficacy of bi-annual intra-articular LBSA0103 injections in patients with knee osteoarthritis.

The objective of this study is to assess the safety and efficacy of repeated intra-articular injection of high molecular weight hyaluronic acid (LBSA0103) at a 26-week interval, in patients with osteoarthritis of the knee. The study was an open-label, single arm, multicentre prospective trial conducted in patients with symptomatic knee osteoarthritis. The intervention consisted of two intra-articular injections of LBSA0103, with the second injection performed 26 weeks after the first injection. The primary outcome was the incidence of adverse drug reactions related to each injection. Assessment of efficacy of repeated injections in terms of maintenance of pain relief was a secondary objective of this study. Of the 185 patients screened, 174 patients received the first injection and 153 patients received both injections of LBSA0103. Nine adverse drug reactions occurred in seven patients (4.02%) after the first injection, while only one adverse drug reaction occurred (0.65%) after the second injection. As a secondary outcome measure, the improvements in the efficacy parameters including total WOMAC score and weight-bearing pain were all significant at both week 13 and 39 compared to the baseline value (P < 0.001), and improvements after the second injection were consistent with those after the initial injection of LBSA0103 (between week 26 and week 39, P < 0.001). Repeated intra-articular injection of LBSA0103 at a 26-week interval is safe without increased risk of adverse drug reactions. Additionally, LBSA0103 is effective in reduction of osteoarthritis knee pain and in maintenance of pain reduction for a 39-week period when a second injection is administered.

Measurement of change on medial and lateral joint gaps by navigation system in multi-radius PS TKA.

BACKGROUND: The purpose of this study was to evaluate the joint gap kinematics in posterior-stabilized total knee arthroplasty (PS TKA). METHODS: Between January 2010 and April 2011, 44 consecutive patients (55 knees) who underwent primary PS TKA using the navigation system were assessed. There were 37 women and 7 men with a mean age at operation of 63 years (range; 58-73 years). After fixation of all components with cement and insertion of polyethylene trial insert, medial and lateral joint gap measurements were carried out without distraction force and separately using a navigation system on each flexion angles. The joint gaps were measured before and after deflation of tourniquet, first with patella everted and then reduced. RESULTS: Deflation of tourniquet did not effect on gap. In patellofemoral joint reduction situation, the medial gap relatively maintained throughout the range of knee motion, but the lateral gap is gradually decreasing with knee flexion from 30° to 120° flexion. However, in patellar eversion situation, the medial gap showed a significant increase and also statistically significantly increased compared with patellar reduced position over 90° knee flexion status, but the lateral gaps are decreased compared with patellofemoral reduction situation throughout the range of knee motion except full flexion status. In more physiologic status that is patella reduced and tourniquet deflated status, the average medial joint gap change was 2.30 ± 1.64 mm and the average lateral joint gap change was 2.90 ± 1.53 mm throughout the range of motion. CONCLUSIONS: Medial and lateral joint gaps showed different patterns with patellar eversion and patellofemoral joint reduction. However, such changes occurred within 3 mm in average throughout whole range of knee motion even with multi-radius femoral component.

Rapid Imaging of Latent Fingerprints Using Biocompatible Fluorescent Silica Nanoparticles.

Fluorescent silica nanoparticles (FSNPs) are synthesized through the Stöber method by incorporating silane-modified organic dye molecules. The modified fluorescent organic dye molecule is able to be prepared by allylation and hydrosilylation reactions. The optical properties of as-prepared FSNPs are shown the similar optical properties of PR254A (allylated Pigment Red 254) and have outstanding photostability. The polyvinylpyrrolidone (PVP) is introduced onto the surface of FSNP to enhance the binding affinity of PVP-coated FSNP for latent fingerprints (LFPs) detection. The simple preparation and easy control of surface properties of FSNPs show potential as a fluorescent labeling material for enhanced latent fingerprint detection on hydrophilic and hydrophobic substrates in forensic science for individual identification.

Clue to Understanding the Janus Behavior of Eumelanin: Investigating the Relationship between Hierarchical Assembly Structure of Eumelanin and Its Photophysical Properties.

The contradictory biological function of eumelanin (photoprotection vs photosensitization) has long been a topic of debate in a wide range of disciplines such as chemistry, physics and biology. For understanding full spectrum of eumelanin's photobiological aspect, revealing how eumelanin's complex structural organization dictates its photophysical properties is critical step. Here, we report a practical approach to controlling the hierarchically assembled structure of natural eumelanin, which leads to disassembly of its structure into subunits and oxidized subunits, respectively. Based on the well-characterized model system, it was possible to systematically determine how the photophysical properties of eumelanin are ruled by its hierarchical assembly organization. Particularly, our experiments reveal that the chemical oxidation of eumelanin's subunits, which leads to delamination of their stacked layer structure, is critical to significantly increase their photochemical reactivity to generate ROS under UV irradiation. This result provides clear experimental evidence that oxidative degradation of eumelanin, which might be induced by phagosomal enzymatic activity in the process of melanomagenesis, is responsible for triggering the negative photobiological role of eumelanin such as ROS source needed for development of malignant melanoma.

Double metal tibial blocks augmentation in total knee arthroplasty.

PURPOSE: Severe uncontained tibial bone defects occurring during total knee arthroplasty are challenging, and which treatment method is the best remains unknown. In this study, clinical and radiographic outcomes of double metal blocks augmentation were examined. METHODS: Between 2004 and 2012, double metal blocks augmentation was carried out in 17 patients with severe asymmetric uncontained tibial bone defects. The first block was attached to the tibial tray with screws, and then the second block was cemented to the first block. Out of 17 patients, 13 (8 primary, 5 revision) were available for final follow-up at a median of 69 months (range 24-99). For clinical assessment, range of motion and Knee Society score were evaluated preoperatively and annually thereafter. At the final follow-up, Western Ontario and McMaster Universities Osteoarthritis Index, Oxford knee, Short Form-36, Lower extremity functional scale, and Lower extremity activity scale scores were evaluated. Radiographic assessment for radiolucent lines at the block-cement-bone interfaces and signs of failure was performed annually using fluoroscopy and standard radiographs. RESULTS: Range of motion and Knee Society score were significantly improved post-operatively. Other clinical outcomes were favourable. Radiolucent lines were seen on fluoroscopy in three knees, but no sign of failure, such as loosening, collapse, or instability, was observed at the final follow-up. CONCLUSIONS: Double metal blocks augmentation is a favourable and useful method, which does not cause mechanical failure or protrusion of the prosthetic because of its modularity, to manage severe asymmetric uncontained proximal tibial bone defects >15 mm in total knee arthroplasty. LEVEL OF EVIDENCE: Case series, Level IV.

Bio-inspired development of a dual-mode nanoprobe for MRI and Raman imaging.

New generation dual-mode imaging probes for MRI and Raman imaging techniques are developed, inspired by the hyper intense contrast enhancing capability in T1 -weighted MRI and characteristic Raman signal of natural melanin. MDA-MB-231cells labeled with dual-mode imaging probe are successfully detected in both T1-weighted MRI and Raman imaging.

Soft template strategy to synthesize iron oxide-titania yolk-shell nanoparticles as high-performance anode materials for lithium-ion battery applications.

Yolk-shell-structured nanoparticles with iron oxide core, void, and a titania shell configuration are prepared by a simple soft template method and used as the anode material for lithium ion batteries. The iron oxide-titania yolk-shell nanoparticles (IO@void@TNPs) exhibit a higher and more stable capacity than simply mixed nanoparticles of iron oxide and hollow titania because of the unique structure obtained by the perfect separation between iron oxide nanoparticles, in combination with the adequate internal void space provided by stable titania shells. Moreover, the structural effect of IO@void@TNPs clearly demonstrates that the capacity retention value after 50 cycles is approximately 4 times that for IONPs under harsh operating conditions, that is, when the temperature is increased to 80 °C.

Bioactive silica nanoparticles reverse age-associated bone loss in mice.

We recently reported that in vitro, engineered 50nm spherical silica nanoparticles promote the differentiation and activity of bone building osteoblasts but suppress bone-resorbing osteoclasts. Furthermore, these nanoparticles promote bone accretion in young mice in vivo. We have now investigated the capacity of these nanoparticles to reverse bone loss in aged mice, a model of human senile osteoporosis. Aged mice received nanoparticles weekly and bone mineral density (BMD), bone structure, and bone turnover were quantified. Our data revealed a significant increase in BMD, bone volume, and biochemical markers of bone formation. Biochemical and histological examinations failed to identify any abnormalities caused by nanoparticle administration. Our studies demonstrate that silica nanoparticles effectively blunt and reverse age-associated bone loss in mice by a mechanism involving promotion of bone formation. The data suggest that osteogenic silica nanoparticles may be a safe and effective therapeutic for counteracting age-associated bone loss. FROM THE CLINICAL EDITOR: Osteoporosis poses a significant problem in the society. Based on their previous in-vitro findings, the authors' group investigated the effects of spherical silica nanoparticles in reversing bone loss in a mouse model of osteoporosis. The results showed that intra-peritoneal injections of silica nanoparticles could increase bone mineral density, with little observed toxic side effects. This novel method may prove important in future therapy for combating osteoporosis.