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[en] In recent years nanoscale metal-organic frameworks (NMOFs) are contributing as an effective material for use in drug delivery and imaging applications due to their porous surfaces and easy surface modifications. In this work, Fe-MIL-88B-NH2 NMOFs were successfully synthesized on facile hydrothermal route and 2-aminoterephthalic acid (NH2-BDC) was employed as a bridging ligand to activate amine functional groups on the surface. Amine functional groups not only serve as a structure stabilizing agent but also enhance the loading efficiency of the doxorubicin (DOX) anticancer drug. A pH responsive DOX release was realized by introducing a positively charged chitosan (Chi) capping layer. Upon Chi-coating, cleavage was observed in the Fe-MIL-88B-NH2 structure at acidic pH, while gel-like insoluble structure was formed at basic pH. By utilizing this phenomenon, a pH responsive DOX release system was developed by using Chi capped Fe-MIL-88B-NH2 NMOFs under the designed pH (4.0–8.0). The results suggest the Chi capped Fe-MIL-88B-NH2 can be a promising candidate for future pH responsive drug delivery systems. (paper)
[en] The objective of the study was to compare three noncoplanar delivery techniques (three-dimensional conformal radiation therapy [3DCRT], intensity-modulated radiation therapy [IMRT], and volumetric-modulated arc therapy [VMAT]) for the delivery of lung stereotactic ablative radiation therapy to peripheral lung tumours.
[en] Drug delivery systems especially stimulus-responsive ones play an important role in medicinal chemistry because most of the cancer drugs have various side effects. In the present research, amine groups bonded to β-cyclodextrin (βCD) were used as a pH-sensitive cap for the cavities of magnetic mesoporous silica nanoparticles. In order to insert βCD cap on the cavities of magnetic mesoporous silica nanoparticles, a host which makes host–guest interaction with βCD was needed. Ethylene diamine chain was used as a host for βCD. Doxorubicin was loaded on Fe3O4@mSiO2@NH2 nanoparticles and then functionalized by βCD. In acidic media, the nitrogens of amine groups were protonated and the repellence among the chains gave rise to more and controlled drug release while in neutral media βCD all of the nitrogens had positive charge and these positive charges gave rise to repellence among chains. These interactions caused to open the chains, and βCD was released which in turn gave rise to the delivery of DOX. The amount of DOX loaded on the Fe3O4@mSiO2@NH2 nanoparticles surface was estimated by thermal gravimetric analysis. The results of drug delivery experiments were interesting which were investigated by ultraviolet–visible spectroscopy. To obtain the hydrodynamic diameter of Fe3O4@mSiO2@βCD, dynamic light scattering technique was used. Furthermore, the cytotoxicity of Fe3O4@mSiO2@βCD was also investigated.
[en] Increasing the permeability of drugs across the cornea is key to improving drug absorption by the eye. This study presents a newly developed in situ gel loaded with nanoparticles, which could achieve controlled drug release and high ocular drug bioavailability by avoiding rapid precorneal clearance. The physicochemical parameters of the formulation were investigated and showed uniform size, physical stability, and favorable rheological and gelling properties. Ex vivo permeation studies revealed significantly higher drug release from the in situ gel loaded with nanoparticles compared to the conventional poloxamer in situ gel and the drug solution. When compared with a marketed formulation, the in situ gel loaded with nanoparticles provided slower controlled release and higher ocular bioavailability of dexamethasone. In conclusion, the developed nanoparticle-loaded in situ gel can successfully increase drug ocular bioavailability by enhancing contact time with the ocular surface and permeation through the cornea. (paper)
[en] The purpose of this study is to examine in a clinical setting a novel formulation of objective functions for intensity-modulated radiotherapy treatment plan multicriteria optimization (MCO) that we suggested in a recent study. The proposed objective functions are extended with dynamic multileaf collimator (DMLC) delivery constraints from the literature, and a tailored interior point method is described to efficiently solve the resulting optimization formulation. In a numerical planning study involving three patient cases, DMLC plans Pareto optimal to the MCO formulation with the proposed objective functions are generated. Evaluated based on pre-defined plan quality indices, these DMLC plans are compared to conventionally generated DMLC plans. Comparable or superior plan quality is observed. Supported by these results, the proposed objective functions are argued to have a potential to streamline the planning process, since they are designed to overcome the methodological shortcomings associated with the conventional penalty-based objective functions assumed to cause the current need for time-consuming trial-and-error parameter tuning. In particular, the increased accuracy of the planning tools imposed by the proposed objective functions has the potential to make the planning process less complicated. These conclusions position the proposed formulation as an alternative to existing methods for automated planning. (paper)
[en] A drug-loaded implantable scaffold is a promising substitute for the treatment of tissue defects after a tumor resection operation. In this work, natural pearl powder with good biocompatibility and osteoconductivity was incorporated into polylactic (PLA) nanofibers via electrospinning, and doxorubicin hydrochloride (DOX) was also loaded in the PLA/pearl scaffold, resulting in a drug-loaded composite nanofibrous scaffold (DOX@PLA/pearl). In vitro drug delivery of DOX from a PLA/pearl composite scaffold was measured and in vitro anti-tumor efficacy was also examined, in particular the effect of the pearl content on both key properties were studied. The results showed that DOX was successfully loaded into PLA/pearl composite nanofibrous scaffolds with different pearl content. More importantly, the delivery rate of DOX kept rising as the pearl content increased, and the anti-tumor efficacy of the drug-loaded scaffold on HeLa cells was improved at an appropriate pearl powder concentration. Thus, we expect that the prepared DOX@PLA/pearl powder nanofibrous mat is a highly promising implantable scaffold that has great potential in postoperative cancer treatment. (paper)
[en] UK NuSTAR is the largest Nuclear Physics project, presently funded by the UK Science and Technology Facilities Council. The project aims at construction and delivery of equipment for the R$3$B, HISPEC, and DESPEC experiments at FAIR. In this contribution, the status of the UK DESPEC work package and related activities will be presented
[en] Interest in stimuli-responsive polymers is steadily gaining increasing momentum especially in the fields of controlled and self-regulated drug delivery. Delivery systems based on these polymers are developed to closely resemble the normal physiological process of the diseased state ensuring optimum drug release according to the physiological need. Also termed 'environmental-sensitive' or 'smart', these polymers experience rapid changes in their microstructure from a hydrophilic to a hydrophobic state triggered by small changes in the environment. The changes are reversible; therefore, the polymer is capable of returning to its initial state as soon as the trigger is removed. Stimuli may occur internally (e.g. a change in pH in certain organs or diseased states, a change in temperature or the presence of specific enzymes or antigens). External stimuli include magnetic or electric fields, light, ultrasound, etc. This review will delve into the various internally and externally stimuli-responsive polymers and the drug delivery systems that exploit them. (topical review)
[en] With the evolution of the field of nanomaterials in the past number of years, it has become apparent that it will be key to future technological developments. However, while there are unlimited research undertakings on nanomaterials, limited research results on nanomaterial costs exist; all in spite of the generous funding that nanotechnology projects have received. There has recently been an exponential increase in the number of studies concerning health-related nanomaterials, considering the various medical applications of nanomaterials that drive medical innovation. This work aims to analyze the effect of the cost factor on acceptability of health-related nanomaterials independently or in relation to material toxicity. It appears that, from the materials studied, those used for cancer treatment applications are more expensive than the ones for drug delivery. The ability to evaluate cost implications improves the ability to undertake research mapping and develop opinions on nanomaterials that can drive innovation.
[en] The dispersion of graphene in water has generally been considered an insurmountable challenge owing to its hydrophobic nature. In this study, a new type of light-sensitive polymer/graphene composite (AzoPEO/β-CD–RGO) was synthesized by the reversible host–guest interaction between azobenzene-terminal poly(ethylene oxide) (AzoPEO) and a β-cyclodextrin (β-CD) host attached to the surface of graphene via hydrogen bonding. In water, the AzoPEO/β-CD–RGO composite not only is well dispersed, but also exhibits reversible dispersion/aggregation behavior triggered by UV and visible light. Moreover, the graphene composite can be used to fabricate a light-responsive graphene-based drug delivery system. This kind of light-responsive graphene composite, which efficiently allows the control of graphene dispersion/aggregation, may find wide applications in the preparation of intelligent drug delivery systems, smart sensors, and switching devices.