The Preparation of Hollow Mesoporous Bioglass Nanoparticles With Excellent Drug Delivery Capacity for Bone Tissue Regeneration

In this work, hollow mesoporous bioglass (HMBG) nanoparticles were prepared in a hexadecyl trimethyl ammonium bromide (CTAB)-cyclonexane-ethanol-water (O/W) emulsion system. The HMBG nanoparticles possessed higher drug storage ability and stable drug release behavior which resulted from HMBG's unique mesoporous structure. The mesoporous structure could be modulated by adjusting the concentration of CTAB. The specific surface area and drug loading efficiency was as high as 749.619 m2g−1 and 55.1%. Besides, in vivo experiments demonstrated that the HMBG nanoparticles could promote the bone tissue regeneration and the drug-loading HMBG nanoparticles possessed better repair capability. The unique structure and properties might make the HMBG nanoparticles good candidates as drug carriers and repair materials for bone tissue regeneration

Preliminary findings on the reliability and validity of the Cantonese Birmingham Cognitive Screen in patients with acute ischemic stroke

BACKGROUND: There are no currently effective cognitive assessment tools for patients who have suffered stroke in the People’s Republic of China. The Birmingham Cognitive Screen (BCoS) has been shown to be a promising tool for revealing patients’ poststroke cognitive deficits in specific domains, which facilitates more individually designed rehabilitation in the long run. Hence we examined the reliability and validity of a Cantonese version BCoS in patients with acute ischemic stroke, in Guangzhou. METHOD: A total of 98 patients with acute ischemic stroke were assessed with the Cantonese version of the BCoS, and an additional 133 healthy individuals were recruited as controls. Apart from the BCoS, the patients also completed a number of external cognitive tests, including the Montreal Cognitive Assessment Test (MoCA), Mini Mental State Examination (MMSE), Albert’s cancellation test, the Rey–Osterrieth Complex Figure Test, and six gesture matching tasks. Cutoff scores for failing each subtest, ie, deficits, were computed based on the performance of the controls. The validity and reliability of the Cantonese BCoS were examined, as well as interrater and test–retest reliability. We also compared the proportions of cases being classified as deficits in controlled attention, memory, character writing, and praxis, between patients with and without spoken language impairment. RESULTS: Analyses showed high test–retest reliability and agreement across independent raters on the qualitative aspects of measurement. Significant correlations were observed between the subtests of the Cantonese BCoS and the other external cognitive tests, providing evidence for convergent validity of the Cantonese BCoS. The screen was also able to generate measures of cognitive functions that were relatively uncontaminated by the presence of aphasia. CONCLUSION: This study suggests good reliability and validity of the Cantonese version of the BCoS. The Cantonese BCoS is a very promising tool for the detection of cognitive problems in Cantonese speakers

Microarchitecture and Nanomechanical Properties of Trabecular Bone After Strontium Administration in Osteoporotic Goats

Strontium (Sr) ralenate is a new agent used for the prevention and treatment of osteoporosis. As a bone-seeking element, 98% of Sr is deposited in the bone and teeth after oral ingestion. However, the effect of Sr treatment on bone microarchitecture and bone nanomechanical properties remains unclear. In this study, 18 osteoporotic goats were divided into four groups according to the treatment regimen: control, calcium alone (Ca), calcium and Sr at 24 mg/kg (Ca + 24Sr), and calcium and Sr at 40 mg/kg (Ca + 40Sr). The effects of Sr administration on bone microarchitecture and nanomechanical properties of trabecular bones were analyzed with micro-CT and nanoindentation test, respectively. Serum Sr levels increased six- and tenfold in the Ca + 24Sr and Ca + 40Sr groups, respectively. Similarly, Sr in the bone increased four- and sixfold in these two groups. Sr administration significantly increased trabecular bone volume fraction, trabecular thickness, and double-labeled new bone area. Sr administration, however, did not significantly change the nanomechanical properties of trabecular bone (elastic modulus and hardness). The data suggested that Sr administration increased trabecular bone volume and improved the microarchitecture while maintaining the intrinsic tissue properties in the osteoporotic goat model

Hydrothermal deposition of hydroxyapatite particles and coatings

The objective of this work was to investigate the conditions that influence the deposition of hydroxyapatite particles by the hydrothermal method. Temperature, time, and the pH of the solution were the key variables examined. This investigation formed a basis for the second part of the work in which the deposition of hydroxyapatite coatings on glass and ceramic surfaces was investigated. Knowledge of the deposition conditions in free solution is expected to greatly facilitate the selection of conditions for the deposition of the coatings. --Introduction, page 4

Solubility of calcium phosphates and related oral minerals by solid titration

abstractpublished_or_final_versionDentistryDoctoralDoctor of Philosoph