ABSTRACT
BACKGROUND: In this work, chitosan (CH) was used to produce a novel coating for Ti6Al4V, the most widely used alloy in orthopedic implants, so as to improve the biological tissue response at the metallic surface. METHODS: The Ti6Al4V surface was sandblasted with alumina particles. CH was chemically modified, via carbodiimide chemistry, using lactobionic and 4-azidebenzoic acid to make it soluble at physiological pH and photocrosslinkable, respectively. The reaction was verified by FTIR, NMR and UV/vis spectroscopy. Ti6Al4V surfaces were coated with solutions of the modified CH and exposed to UV light, causing polymer crosslinking and formation of a hydrogel on the surface. The crosslinking reaction was monitored by FTIR at different exposure times. Coating morphology was observed by SEM. The coating's cytocompatibility was determined in vitro through the culture of rat bone marrow mesenchymal stem cells, using an MTT assay, with their morphology assessed by SEM. RESULTS: The developed coating behaved as a hydrogel on the Ti6Al4V and was stable on the surface. FTIR and NMR confirmed the crosslinking mechanism, based on an arile ring expansion, and subsequent reaction with the CH amine groups. Furthermore, the coating was able to support cell proliferation and osteogenic differentiation. CONCLUSIONS: UV crosslinking of CH is easy to apply and has potential for future metallic implant surface modifications. Due to its nature as a hydrogel, the coating could be used for further studies in the encapsulation of bioactive molecules to improve osteogenic potential at the tissue-implant interface.
Subject(s)
Chitosan/chemistry , Coated Materials, Biocompatible/chemistry , Cross-Linking Reagents/chemistry , Titanium/chemistry , Alloys , Animals , Cell Proliferation/drug effects , Coated Materials, Biocompatible/pharmacology , Coated Materials, Biocompatible/toxicity , Cross-Linking Reagents/pharmacology , Cross-Linking Reagents/toxicity , Male , Mesenchymal Stem Cells , Rats , Rats, Sprague-Dawley , Surface PropertiesABSTRACT
OBJECTIVE: Centripetal obesity is associated with systemic low-grade inflammation and an increased cardiovascular risk. Patients in long-term remission of Cushing's syndrome (CS) report persisting abdominal fat accumulation. However, this has previously not been adequately objectified. Therefore, we investigated the adipose tissue distribution and adipocytokine profiles of patients in long-term remission of CS. DESIGN: Cross-sectional case-control study in a tertiary referral centre. PATIENTS: Fifty-eight patients, in remission of CS for at least 5 years, were compared to 58 age-, gender- and BMI-matched healthy control subjects. MEASUREMENTS: Measures of body composition (assessed with clinical evaluation and dual-energy X-ray absorptiometry (DEXA) scanning) and serum adipocytokine profiles. RESULTS: Compared to the matched control subjects, patients in long-term remission of CS had a greater waist circumference (P < 0·01), a smaller thigh circumference (P < 0·01), a higher waist-to-hip ratio (P < 0·01) and a higher hip-to-thigh ratio (P < 0·01). As measured with DEXA scanning, patients had a higher percentage of truncal fat mass (P = 0·01), and the truncal fat mass to leg fat mass ratio was greater (P < 0·01). Patients had lower adiponectin levels (P < 0·01), higher leptin levels (P < 0·01) and higher resistin levels (P = 0·04) than control subjects. CONCLUSION: Even after long-term remission, patients who suffered from CS in the past continue to have a centripetal adipose tissue distribution and an adverse adipokine profile. This is independent of aetiology of the CS, treatment strategies, hormonal deficiencies and comorbidity, and probably contributes to the persistent increased cardiovascular risk.
Subject(s)
Abdominal Fat/metabolism , Body Fat Distribution , Cushing Syndrome/metabolism , Cushing Syndrome/rehabilitation , Obesity, Abdominal/metabolism , Abdominal Fat/pathology , Adipokines/metabolism , Adult , Cardiovascular Diseases/etiology , Cardiovascular Diseases/metabolism , Case-Control Studies , Cross-Sectional Studies , Cushing Syndrome/drug therapy , Cushing Syndrome/epidemiology , Female , Glucocorticoids/therapeutic use , Humans , Male , Metabolic Syndrome/epidemiology , Metabolic Syndrome/metabolism , Middle Aged , Obesity, Abdominal/epidemiology , Remission Induction , Risk Factors , Time FactorsABSTRACT
An innovative program developed to work with families in which substance use during pregnancy leads to Child Protective Services involvement is introduced in this article. The Vulnerable Infants Program of Rhode Island (VIP-RI) was established to facilitate permanency planning for substance-exposed infants by focusing on the interface of social service systems with one another and with the families affected by perinatal substance use. Permanent placement within the time frame mandated by federal legislation places increased pressures on parents and the social service systems designed to provide them with assistance. The Vulnerable Infants Program of Rhode Island promotes collaboration, coordination, and communication among social service systems engaged with families of substance-exposed infants. The Vulnerable Infants Program of Rhode Island works to increase the efficacy of social service systems in order to optimize the resources that are available to a family in their attempts at reunification with their infant. Case examples illustrate the complexities of the families of substance-exposed infants, the breadth of social service systems that become involved with these families, and the vastly different placement outcomes that substance-exposed infants may experience.
