Innovative Nanotechnology in Drug Delivery Systems for Advanced Treatment of Posterior Segment Ocular Diseases.

Funduscopic diseases, including diabetic retinopathy (DR) and age-related macular degeneration (AMD), significantly impact global visual health, leading to impaired vision and irreversible blindness. Delivering drugs to the posterior segment of the eye remains a challenge due to the presence of multiple physiological and anatomical barriers. Conventional drug delivery methods often prove ineffective and may cause side effects. Nanomaterials, characterized by their small size, large surface area, tunable properties, and biocompatibility, enhance the permeability, stability, and targeting of drugs. Ocular nanomaterials encompass a wide range, including lipid nanomaterials, polymer nanomaterials, metal nanomaterials, carbon nanomaterials, quantum dot nanomaterials, and so on. These innovative materials, often combined with hydrogels and exosomes, are engineered to address multiple mechanisms, including macrophage polarization, reactive oxygen species (ROS) scavenging, and anti-vascular endothelial growth factor (VEGF). Compared to conventional modalities, nanomedicines achieve regulated and sustained delivery, reduced administration frequency, prolonged drug action, and minimized side effects. This study delves into the obstacles encountered in drug delivery to the posterior segment and highlights the progress facilitated by nanomedicine. Prospectively, these findings pave the way for next-generation ocular drug delivery systems and deeper clinical research, aiming to refine treatments, alleviate the burden on patients, and ultimately improve visual health globally.

Development of graphitic carbon nitride quantum dots-based oxygen self-sufficient platforms for enhanced corneal crosslinking.

Keratoconus, a disorder characterized by corneal thinning and weakening, results in vision loss. Corneal crosslinking (CXL) can halt the progression of keratoconus. The development of accelerated corneal crosslinking (A-CXL) protocols to shorten the treatment time has been hampered by the rapid depletion of stromal oxygen when higher UVA intensities are used, resulting in a reduced cross-linking effect. It is therefore imperative to develop better methods to increase the oxygen concentration within the corneal stroma during the A-CXL process. Photocatalytic oxygen-generating nanomaterials are promising candidates to solve the hypoxia problem during A-CXL. Biocompatible graphitic carbon nitride (g-C3N4) quantum dots (QDs)-based oxygen self-sufficient platforms including g-C3N4 QDs and riboflavin/g-C3N4 QDs composites (RF@g-C3N4 QDs) have been developed in this study. Both display excellent photocatalytic oxygen generation ability, high reactive oxygen species (ROS) yield, and excellent biosafety. More importantly, the A-CXL effect of the g-C3N4 QDs or RF@g-C3N4 QDs composite on male New Zealand white rabbits is better than that of the riboflavin 5'-phosphate sodium (RF) A-CXL protocol under the same conditions, indicating excellent strengthening of the cornea after A-CXL treatments. These lead us to suggest the potential application of g-C3N4 QDs in A-CXL for corneal ectasias and other corneal diseases.

[Values of brain natriuretic peptide and N-terminal pro-brain natriuretic peptide in evaluation of cardiac function in children with congenital heart disease].

OBJECTIVE: To study the values of brain natriuretic peptide (BNP) and N-terminal pro-brain natriuretic peptide (NT-proBNP) in the evaluation of cardiac function in children with congenital heart disease (CHD). METHODS: Seventy-one children with CHD were classified to two groups: congestive heart failure (CHF) (n=23 ) and non-CHF (n=48). Thirty-five age-matched normal children were used as the control group. Plasma BNP content was measured using a microparticle enzyme immunoassay (MEIA) on the AxSYM. Plasma NT-proBNP content was measured using an automated electrochemiluminescence immunoassay on a Roche Modular Analytics E170 analyzer. Echocardiographic parameters, including left ventricular end diastolic dimension index (LVEDDI) and left ventricular ejection fraction (LVEF), were measured. RESULTS: Plasma BNP and NT-proBNP contents in the CHF group were significantly higher than those in the non-CHF group (P<0.01). The non-CHF group had higher plasma BNP and NT-proBNP contents than the control group (P<0.01). LogBNP and LogNT-proBNP values were negatively correlated with the LVEF in the CHF group (r=-0.64, r=-0.67 respectively, P<0.01), and they were positively correlated with the LVEDDI (r=0.58, r=0.76 respectively, P<0.01). In the non-CHF group, LogBNP and LogNT-proBNP values were not correlated with the LVEF, but a positive correlation was found between the LogNT-proBNP value and the LVEDDI (r=0.35, P<0.05). Using plasma BNP content > or =149.8 pg/mL and NT-proBNP content > or =820.1 pg/mL as cut-off values for diagnosing CHF respectively, the sensitivities were 87.0 % and 91.3% respectively, the specificities were 91.7% and 97.9% respectively, and the areas under the ROC curves were 0.935 and 0.987 respectively. CONCLUSIONS: Both BNP and NT-proBNP can be useful in assessment of cardiac function and diagnosis of CHF in children with CHD. NT-proBNP appears to be more sensitive and specific in the diagnosis of CHF than BNP.

[Experimental study on repair of bone defect in femoral head by enhanced autogenous bone combined with bone morphogenetic protein].

OBJECTIVE: To compare and evaluate the capability of pure autogenous bone and the enhanced autogenous bone combined with bone morphogenetic protein in bone repair of femoral head. METHODS: Eighteen femoral heads of 9 dogs were drilled by trephine, 4 mm in diameter, followed by respective implantations of autogenous bone grafting (group B) and of the enhanced autogenous bone composite, combined with bone morphogenetic protein (group C), with the self-repair of bone defect as the control (group A). Three, six, nine weeks after the operation, radiological examination, computerized tomography, light and electronic microscopes were performed to investigate the bone healing of the defect in the femoral head. RESULTS: In group A, it could be observed that there was hematoma organization and delayed woven bone formation in the 3rd week after operation, and there was little replacement of woven bone by bone trabecula in the 9th week; in group B, the autogenous bone implanted were dead in the 3rd week and maintained in situ in the 9th week; in group C, active new bone formation, either endochondral or intramembranous ossification, was found in the 3rd week and entire repair of the bone defect by bone trabecula in the 9th week after operation. CONCLUSION: The enhanced autogenous bone combined with bone morphogenetic protein could promote reconstruction of the bone defect in femoral head, superior to pure autogenous bone which could provide a framework for the new bone formation.