Design and fabrication of dysprosium impregnated polyvinyl alcohol hydrogels. Physiochemical, mechanical, bioimaging and in vitro evaluation.

Tissue engineering has gained prominence during the past decade since it offers a key solution to defects associated with the tissue regeneration. The limited healing potential of the cartilage tissue damage has significant clinical implications. Herein, dysprosium (Dy3+) impregnated polyvinyl alcohol (PVA) hydrogels have been developed to enhance the therapeutic efficacy, enabling simultaneous diagnostic imaging and antibacterial drug delivery for potential applications in articular cartilage. Based on the favorable imaging features, Dy3+ impregnated PVA hydrogels with enhanced stability were formed through successive steps of repeated cycles of freezing at - 30 °C for 21 h, thawing at 25 °C for 4 h and lyophilization. The tensile and compression tests of the hydrogels respectively determined a maximum of 3.88 and 1.58 MPa, which reflected better compatibility towards cartilage. The hydrogels fetched a sustained drug release for a period of 12 h with an associated swelling ratio of 80%. The potential of the resultant hydrogels in image diagnosis has been deliberated through their blue and yellow emissions in the visible region. Further, the computed tomography (CT) and magnetic resonance imaging characteristics of the hydrogels respectively accomplished a maximum of 343 Hounsfiled units (HU) and relaxivity of 7.25 mM-1s-1. The cytocompatibility of the hydrogels is also determined through in vitro tests performed in Murine pro B cell line (BA/F3) and human Megakaryocyte cell line (Mo7e) cell lines.

Intra-arterial chemotherapy for retinoblastoma in 70 eyes: outcomes based on the international classification of retinoblastoma.

OBJECTIVE: To analyze our 5-year experience of intra-arterial chemotherapy (IAC) for retinoblastoma as primary or secondary therapy. DESIGN: Retrospective interventional case series. PARTICIPANTS: A total of 70 eyes of 67 patients. INTERVENTION: Ophthalmic artery chemotherapy infusion under fluoroscopic guidance was performed using melphalan (3, 5, or 7.5 mg) in every case, with additional topotecan (1 mg) and/or carboplatin (30 or 50 mg) as necessary. MAIN OUTCOME MEASURES: Tumor control and treatment complications. RESULTS: The mean patient age at IAC was 30 months. The treatment was primary in 36 eyes and secondary in 34 eyes. Those primary therapy eyes were classified according to the International Classification of Retinoblastoma (ICRB) as group A (n = 0), B (n = 1), C (n = 4), D (n = 17), or E (n = 14). The secondary therapy eyes had failed previous intravenous chemotherapy (n = 34) in every case. Each eye received a mean of 3 IAC sessions per eye (median, 3; range, 1-7 sessions). After IAC with a mean follow-up of 19 months, globe salvage was achieved in 72% of primary-treated cases and in 62% of secondary-treated cases. Specifically, primary therapy achieved globe salvage for group B (100%), group C (100%), group D (94%), and group E (36%). Of all 70 eyes, complete regression was achieved for solid tumor in 48 of 51 eyes (94%), subretinal seeds in 40 of 42 eyes (95%), and vitreous seeds in 34 of 39 eyes (87%). After each catheterization (n = 198), the main complications included transient eyelid edema (5%), blepharoptosis (5%), and forehead hyperemia (2%). More lasting complications included vitreous hemorrhage (2%), branch retinal artery obstruction (1%), ophthalmic artery spasm with reperfusion (2%), ophthalmic artery obstruction (2%), partial choroidal ischemia (2%), and optic neuropathy (<1%). Over the past 3 years, the combined incidence of ophthalmic, retinal, and choroidal vascular ischemia was reduced to 1%. There was no patient with stroke, seizure, neurologic impairment, limb ischemia, secondary leukemia, metastasis, or death. CONCLUSIONS: Five-year experience with IAC indicates that this technique is remarkably effective for the management of retinoblastoma as both a primary and a secondary treatment.