Tuning the size of cylindrical micelles from poly(l-lactide)-b-poly(acrylic acid) diblock copolymers based on crystallization-driven self-assembly

A series of poly(l-lactide)-b-poly(acrylic acid) (PLLA-b-PAA) diblock copolymers with a range of hydrophobic or hydrophilic block lengths were designed in order to tune the size of the resultant cylindrical micelles using a crystallization-driven self-assembly (CDSA) approach. The precursor poly(l-lactide)-b-poly(tetrahydropyran acrylate) (PLLA-b-PTHPA) was synthesized by a combination of ring-opening polymerization (ROP) and reversible addition-fragmentation chain transfer (RAFT) polymerization. The CDSA process was carried out in a tetrahydrofuran/water (THF/H2O) mixture during the hydrolysis of PTHPA block at 65 °C using an evaporation method. A majority of PLLA-b-PAA diblock copolymers resulted in the formation of cylindrical micelles with narrow size distributions (Lw/Ln < 1.30) as determined by transmission electron microscopy (TEM) and dynamic light scattering (DLS). Furthermore, the length of PLLA block was found to control the length of the resultant cylindrical micelles while the length of PAA block governed their widths. Synchrotron small-angle X-ray scattering (SAXS) further proved that the length increase of these cylinders was a consequence of the decreasing PLLA block lengths. The crystalline core nature of these cylinders was characterized by wide-angle X-ray diffraction (WAXD), and the relative core crystallinity was calculated to compare different samples. Both the hydrophobic weight fraction and the relative core crystallinity were found to determine the geometry of the formed PLLA-b-PAA cylindrical micelles. Finally, changing the pH conditions of the CDSA process was found to have no significant effect on tuning the resultant dimensions of the cylinders

Molecular simulation study of the effect of various additives on salbutamol sulfate crystal habit

10.1021/mp200277uMolecular Pharmaceutics851910-1918MPOH

Integrative treatment in persons with intellectual disability and mental health problems.

Contains fulltext : 53317.pdf (publisher's version ) (Closed access)BACKGROUND: Clinical experience has proven thus far that a monodisciplinary treatment approach to behavioural and psychiatric problems in persons with intellectual disability (ID), such as psychotropic medication or behaviour modification programmes, has yielded limited success. It is clear that the complexity of behavioural and psychiatric problems in this population calls for a treatment approach from different perspectives. METHODS: A multidimensional treatment approach to the persons with ID who suffer from behaviour problems and psychiatric disorders is described. RESULTS: Four dimensions - biological, psychological, social and developmental - are represented as well in an integrative diagnosis as in an integrative treatment, embodied by cooperation of different professionals, such as a psychiatrist, psychologist, pedagogues, social worker, nurse and, where possible, the person's caretakers. The developmental dimension receives a salient attention of assessors. By introducing the developmental dimension in diagnostics and treatment, the bio-psycho-social dimensions are set in a new context, more appropriate for persons with ID. CONCLUSION: The integrative treatment should not be primarily directed towards the symptoms of the disorder but towards restoring a person's mental well-being. The disorder is combated through treatment of the underlying processes that have led to its onset. Different treatment methods from different perspectives may be applied. Strategy and methodological procedures of an integrative treatment are discussed by way of case presentations