Silica nanoparticles: A review of their safety and current strategies to overcome biological barriers

Silica nanoparticles (SNP) have gained tremendous attention in the recent decades. They have been used in many different biomedical fields including diagnosis, biosensing and drug delivery. Medical uses of SNP for anti-cancer, anti-microbial and theranostic applications are especially prominent due to their exceptional performance to deliver many different small molecules and recently biologics (mRNA, siRNA, antigens, antibodies, proteins, and peptides) at targeted sites. The physical and chemical properties of SNP such as large specific surface area, tuneable particle size and porosity, excellent biodegradability and biocompatibility make them an ideal drug delivery and diagnostic platform. Based on the available data and the pre-clinical performance of SNP, recent interest has driven these innovative materials towards clinical application with many of the formulations already in Phase I and Phase II trials. Herein, the progress of SNP in biomedical field is reviewed, and their safety aspects are analysed. Importantly, we critically evaluate the key structural characteristics of SNP to overcome different biological barriers including the blood-brain barrier (BBB), skin, tumour barrier and mucosal barrier. Future directions, potential pathways, and target areas towards rapid clinical translation of SNP are also recommended.

Virus-like silica nanoparticles enhance macromolecule permeation in vivo

Nanoparticle based permeation enhancers have the potential to improve the oral delivery of biologics. Recently, solid silica nanoparticles were discovered to improve the intestinal permeability of peptides and proteins via transient opening of the gut epithelium. In this study, we have developed small-sized (∼60 nm) virus-like silica nanoparticles (VSNP) as a reversible and next generation non-toxic permeation enhancer for oral delivery of biologics. Our results show that the anionic VSNP showed a better permeation-enhancing effect than the same sized spherical Stöber silica nanoparticles (∼60 nm) by enhancing the apparent insulin permeability by 1.3-fold in the Caco-2 monolayer model and by 1.2-fold in the Caco-2/MTX-HT-29 co-culture model. In vivo experiments in healthy mice demonstrated that anionic VSNP significantly enhanced the permeation of fluorescently labelled 4 kDa dextran after oral administration compared to Stöber nanoparticles and positively charged VSNP. The results indicated that the nanoscale surface roughness is an important consideration when designing nanoparticle-based permeation enhancers. Overall, our study shows for the first time that small-sized (∼60 nm) VSNP with nanoscale surface roughness can be used as a non-toxic permeation enhancer for oral delivery of therapeutic peptides and proteins.

Embitterment and Aggression in Psychotherapy Patients

Introduction

Embitterment is an emotion which is known to everybody in reaction to injustice, humiliation, and breach of trust. In greater intensity it can cause severe suffering for the affected person and the social envirnment, can result in lasting impairment, and even lead to dysfunctional behavior, including aggression. Embittered patients need therapeutic help and are regularly seen in psychotherapy. The problem is often not properly recognized, because of the multiple accompanying symptoms and accusations against the environment.

Objectives

Goal of the present study was to learn about the prevalence of embitterment in psychotherapy patients

Methods

Outpatients in routine psychotherapy filled in the PTED scale (post-traumatic embitterment disorder selfrating scale), the K-FAF (short assessment of aggression) and the SCL-90 (symptom-checklist-90). Additionally, sociodemographic data were available.

Results

Included were 118 patients, of whom 22% showed a relevant severity of embitterment, 23.7% a relevant score for reactive aggression, and 54.2% a relevant score for irritable aggression. There was a significant correlation between the PTED scale and the aggression scale.

Conclusions

The data show that embitterment and related aggression are frequent phenomena in psychotherapy patients. Therapists should be aware of this emotion and take proper action to diagnose embitterment and aggressive ideation, which are often covered by other complaints. Special treatments are needed, as the aggressive and negativistic features of embitterment complicate the psychotherapy process.

Disclosure

No significant relationships.

The role of chronic disorders in psychotherapy

Introduction

Many mental disorders take a chronic course, associated with disability and/or participation restrictions. This is well recognized in social psychiatry. It is assumed that in psychotherapy milder disorders are seen, but there are no data available in this regard. In a survey in outpatient psychotherapy the rate of patients with chronic disorders and associated impairment was assessed.

Objectives

Goal of the present study was to assess the prevalence and meaning of long term and prevailing disorders in psychotherapy

Methods

A total of 131 psychotherapists (43.5% psychodynamic, 55.7% cognitive behavior therapy) reported about 322 outpatients. Therapists were interviewed in person by two research psychotherapists in regard to illness characteristics of unselected patients.

Results

The duration of illness was longer than 1 year in 98.1% of patients or longer than a decade in 54.5%. In the judgement of the therapists 79% of disorders had a chronic or recurrent course. In 25% there were relevant participation impairments in regard to daily activities, leisure time, social relations, or work. About one quarter had already been in inpatient treatment.

Conclusions

The data show that chronic disorders are the rule rather than the exception in psychotherapy. This requires a multidimensional and interdisciplinary treatment approach, including sociomedical interventions in order to sustain participation in life. This should be recognized in the treatment concepts and also get proper attention in the education and reimbursement of psychotherapists.

Disclosure

No significant relationships.

Minimal emotional dysfunctions (MED) in personality disorders

The concept of minimal emotional dysfunctions (MED) refers to traditional psychopathology in order to describe, classify, and understand personality disorders. Emotional dysfunctions encompass disorders of affect predominance, production, expression, experience, modulation, and regulation. MED can explain the dimensional nature of personality disorders, their multidimensionality and problems with categorical classifications. It can stimulate research on the etiology of personality disorders in reference to modern developmental brain research and trauma psychology. It can guide new developments in pharmacotherapy and psychotherapy. It is suggested to focus on MED in future developments of the description and classification of personality disorders.

Fast versus slow onset of depressive episodes: A clinical criterion for subtyping patients with major depression

Purpose:

The speed of onset of depressive episodes is a clinical aspect of affective disorders that has not been sufficiently investigated. Thus, we aimed to explore whether patients with fast onset of the full-blown depressive symptomatology (≤ 7 days) differ from those with slow onset (> 7 days) with regard to demographic and clinical aspects.

Subjects and methods:

Data were obtained within an observational study conducted in outpatients with major depression who were treated with duloxetine (30–120 mg/day). Onset of depression (without any preceding critical life event) was fast in 416 (less than one week) and slower in 2220 patients.

Results:

Compared to patients with slow onset, those with fast onset of depression had more suicide attempts in the previous 12 months (2.7% versus 1.3%, P = 0.046) and less somatic comorbidity (61.7% versus 74.1%, P < 0.0001). In addition, they were slightly younger at onset of depression (mean ± SD 40.2 ± 14.6 versus 42.8 ± 14.2 years, P < 0.001) and used analgesics at baseline significantly less frequently (22.8% versus 33.4%, P < 0.0001).

Discussion and conclusion:

The speed of onset of depression has to be regarded as a relevant clinical characteristic in patients with unipolar depression.

Genetic selection for bovine chromosome 18 haplotypes associated with divergent somatic cell score affects postpartum reproductive and metabolic performance

The susceptibility of animals to periparturient diseases has a great effect on the economic efficiency of dairy industries, on the frequency of antibiotic treatment, and on animal welfare. The use of selection for breeding cows with reduced susceptibility to diseases offers a sustainable tool to improve dairy cattle farming. Several studies have focused on the association of distinct bovine chromosome 18 genotypes or haplotypes with performance traits. The aim of this study was to test whether selection of Holstein Friesian heifers via SNP genotyping for alternative paternal chromosome 18 haplotypes associated with favorable (Q) or unfavorable (q) somatic cell scores influences postpartum reproductive and metabolic diseases. Thirty-six heifers (18 Q and 18 q) were monitored from 3 wk before calving until necropsy on d 39 (± 4 d) after calving. Health status and rectal temperature were measured daily, and body condition score and body weight were assessed once per week. Blood samples were drawn twice weekly, and levels of insulin, nonesterified fatty acids, insulin-like growth factor-I, growth hormone, and β-hydroxybutyrate were measured. Comparisons between the groups were performed using Fisher's exact test, chi-squared test, and the GLIMMIX procedure in SAS. Results showed that Q-heifers had reduced incidence of metritis compared with q-heifers and were less likely to develop fever. Serum concentrations of β-hydroxybutyrate were lower and insulin-like growth factor-I plasma concentrations were higher in Q- compared with q-heifers. However, the body condition score and withers height were comparable between haplotypes, but weight loss tended to be lower in Q-heifers compared with q-heifers. No differences between the groups were detected concerning retained fetal membranes, uterine involution, or onset of cyclicity. In conclusion, selection of chromosome 18 haplotypes associated with a reduced somatic cell score resulted in a decreased incidence of postpartum reproductive and metabolic diseases in this study. The presented data add to the existing knowledge aimed at avoiding negative consequences of genetic selection strategies in dairy cattle farming. The underlying causal mechanisms modulated by haplotypes in the targeted genomic region and immune competence necessitate further investigation.

Super-Resolution Microscopy Unveils Dynamic Heterogeneities in Nanoparticle Protein Corona

The adsorption of serum proteins, leading to the formation of a biomolecular corona, is a key determinant of the biological identity of nanoparticles in vivo. Therefore, gaining knowledge on the formation, composition, and temporal evolution of the corona is of utmost importance for the development of nanoparticle-based therapies. Here, it is shown that the use of super-resolution optical microscopy enables the imaging of the protein corona on mesoporous silica nanoparticles with single protein sensitivity. Particle-by-particle quantification reveals a significant heterogeneity in protein absorption under native conditions. Moreover, the diversity of the corona evolves over time depending on the surface chemistry and degradability of the particles. This paper investigates the consequences of protein adsorption for specific cell targeting by antibody-functionalized nanoparticles providing a detailed understanding of corona-activity relations. The methodology is widely applicable to a variety of nanostructures and complements the existing ensemble approaches for protein corona study.

[Side Effects of Occupational Group Therapy]

Background: Occupational therapy is an important co-therapy in psychiatric therapy. It is a common belief that no risks are associated with occupational therapy. Negative effects caused by group therapy, especially occupational therapy, have not been in the focus of research yet. In this study we want to illustrate possible types and intensities of group side effects through occupational therapy. Patients and Methods: Patients of an inpatient rehabilitation facility filled out the Adverse Treatment Reaction Group Checklist. The checklist contains 47 items divided in six dimensions: group size, content, group participants, group outcome and global. The self-rating used a 5-point likert scale (0 = not at all; 4 = very much, extremely stressful) and gives information about types and intensities of the side effects. Results: 88.9 % of 45 patients reported negative effects of occupational group therapy. 28.9 % of the patients rated the side effect as at least severe. Discussion: Occupational therapy is associated with side effects as every other group therapy. Possible side effects caused by group therapy should be considered while planning and implementing occupational therapy.

[Undesired treatment effects in behavior group therapy: Frequency and spectrum]

BACKGROUND

Psychotherapy not only has positive but also negative effects, which is especially true for group psychotherapy due to psychodynamic and interactional processes.

METHODS

Using the UE-G questionnaire 71 patients who participated in cognitive behavioral group psychotherapy reported on negative experiences in the context of the group therapy. The answers were then validated in a qualitative interview.

RESULTS

Of the patients 98.6% reported about at least one negative experience and 43.7% about severe or extremely severe negative experiences. Most prominent was the induction of hopelessness and demoralization by what patients saw and heard from other patients in the group.

CONCLUSION

Burdensome and therefore undesired treatment effects are regularly seen in group psychotherapy, because of treatment or patient related factors. In any case they must be taken into account during treatment, in the training of group psychotherapists and in quality control.

The effects of perceived USB-delay for sensor and embedded system development

Perceiving delay in computer input devices is a problem which gets even more eminent when being used in healthcare applications and/or in small, embedded systems. Therefore, the amount of delay found as acceptable when using computer input devices was investigated in this paper. A device was developed to perform a benchmark test for the perception of delay. The delay can be set from 0 to 999 milliseconds (ms) between a receiving computer and an available USB-device. The USB-device can be a mouse, a keyboard or some other type of USB-connected input device. Feedback from performed user tests with 36 people form the basis for the determination of time limitations for the USB data processing in microprocessors and embedded systems without users' noticing the delay. For this paper, tests were performed with a personal computer and a common computer mouse, testing the perception of delays between 0 and 500 ms. The results of our user tests show that perceived delays up to 150 ms were acceptable and delays larger than 300 ms were not acceptable at all.

Inhibiting Notch Activity in Breast Cancer Stem Cells by Glucose Functionalized Nanoparticles Carrying γ-secretase Inhibitors

Cancer stem cells (CSCs) are a challenge in cancer treatment due to their therapy resistance. We demonstrated that enhanced Notch signaling in breast cancer promotes self-renewal of CSCs that display high glycolytic activity and aggressive hormone-independent tumor growth in vivo. We took advantage of the glycolytic phenotype and the dependence on Notch activity of the CSCs and designed nanoparticles to target the CSCs. Mesoporous silica nanoparticles were functionalized with glucose moieties and loaded with a γ-secretase inhibitor, a potent interceptor of Notch signaling. Cancer cells and CSCs in vitro and in vivo efficiently internalized these particles, and particle uptake correlated with the glycolytic profile of the cells. Nanoparticle treatment of breast cancer transplants on chick embryo chorioallantoic membranes efficiently reduced the cancer stem cell population of the tumor. Our data reveal that specific CSC characteristics can be utilized in nanoparticle design to improve CSC-targeted drug delivery and therapy.

Mesoporous silica nanoparticles in tissue engineering – a perspective

In this review, we summarize the latest developments and give a perspective on future applications of mesoporous silica nanoparticles (MSNs) in regenerative medicine. MSNs constitute a flexible platform for controlled delivery of drugs and imaging agents in tissue engineering and stem cell therapy. We highlight the recent advances in applying MSNs for controlled drug delivery and stem cell tracking. We touch upon novel functions of MSNs in real time imaging of drug release and biological function, and as tools to control the chemical and mechanical environment of stem cells. We discuss the need for novel model systems for studying biofunctionality and biocompatibility of MSNs, and how the interdisciplinary activities within the field will advance biotechnology research.

[Minimal cerebral dysfunctions and ADHD in adulthood]

Attention deficit hyperactivity disorder (ADHD) is of great importance not only in children but also in adults; however, despite extensive research there are still many unsolved questions with respect to the diagnosis. Patients not only suffer from attention deficits and hyperactivity but also a variety of other problems, such as dyspraxia, problems with stimulus discrimination, dysgrammatism, legasthenia, or motor coordination problems. Furthermore, there are also psychopathological disorders, such as problems with memory, formal thinking, emotional modulation, drive and vegetative stability, in the sense of a psycho-organic syndrome. Such syndromes have long been known in psychiatry under terms, such as complex capacity disorders, minimal cerebral dysfunction (MCD), minimal brain dysfunction (MBD), mild psycho-organic syndrome, psycho-organic axis syndrome, mild cognitive impairment, developmental disorder and developmental biological syndrome. Etiological data with respect to genetics and early childhood brain trauma support the notion of a psychobiological disorder for complex cerebral dysfunction in the sense of a psycho-organic syndrome. Depending on the individual life and work situation, these additional symptoms of ADHD are in many cases of greater relevance for life adjustment than the core symptoms, depending on the individual life and work situations. The concept of minimal cerebral dysfunction describes the ADHD problem better and has a direct bearing on the diagnosis, therapy and sociomedical care of the patients.

Diffusion and Molecular Exchange in Hollow Core-Shell Silica Nanoparticles

The diffusion behavior of small molecules in hollow core-shell nanocapsules was studied using pulsed field gradient NMR. By purposefully selecting the liquid saturating the hollow core and the porous shell and the solvent between the nanocapsules, two different situations corresponding to the excluded and admitted molecular exchange between the intra- and intercapsule liquids at the external boundary of the nanoparticles were covered. In the former case, corresponding to the reflective boundary condition for the molecules approaching the nanocapsule boundary, restricted diffusion in the complex pore space formed by the hollow core and the mesoporous shell was observed. The time-dependent diffusivities measured in the experiment were inter-related with the geometry of the intraparticle pore space. The thus assessed structural information was found to be in a good agreement with that provided by electron microscopy. In the case of the molecular exchange occurring between the two pools of molecules in the nanocapsules and between them, the diffusive dynamics of only the molecules remaining in the nanocapsules during the entire observation times was studied.

Mesoporous silica particle-PLA-PANI hybrid scaffolds for cell-directed intracellular drug delivery and tissue vascularization

Instructive materials are expected to revolutionize stem cell based tissue engineering. As many stem cell cues have adverse effects on normal tissue homeostasis, there is a need to develop bioactive scaffolds which offer locally retained and cell-targeted drug delivery for intracellular release in targeted cell populations. Further, the scaffolds need to support vascularization to promote tissue growth and function. We have developed an electrospun PLA-PANI fiber scaffold, and incorporated mesoporous silica nanoparticles within the scaffold matrix to obtain cell-targeted and localized drug delivery. The isotropy of the scaffold can be tuned to find the optimal morphology for a given application and the scaffold is electroactive to support differentiation of contractile tissues. We demonstrate that there is no premature drug release from particles under physiological conditions over a period of one week and that the drug is released upon internalization of particles by cells within the scaffold. The scaffold is biocompatible, supports muscle stem cell differentiation and cell-seeded scaffolds are vascularized in vivo upon transplantation on the chorioallantoic membrane of chicken embryos. The scaffold is a step towards instructive biomaterials for local control of stem cell differentiation, and tissue formation supported by vascularization and without adverse effects on the homeostasis of adjacent tissues due to diffusion of biological cues.

Vesicular Phase Behaviour in Ionic Surfactant Systems with Organic Counter-ions

Phase diagrams at 298.2 K were determined for aqueous systems of alkylamines and alkanoic acids in equimolecular ratio, i.e. for alkylammonium alkanoates. The bilayer structural evolution for these ionic surfactants with organic counter-ions in water was studied using transmission electron microscopy (TEM), optical microscopy, small-angle X-ray scattering (SAXS) and rheological measurements. The formed vesicles are highly viscoelastic and have a yield stress value. In the pentylammonium nonanoate-water system at higher contents, the vesicles collapse to micelles, while in the hexylammonium nonanoate-water and in the pentylammonium decanoate systems, a transition to a fully expressed lamellar phase is observed. The results are discussed in terms of electrostatic interactions and membrane flexibility.

[Medical rehabilitation by general practitioners in patients with chronic mental disorders]

BACKGROUND

Rehabilitation medicine is the medical specialty for the prevention, diagnosis and treatment of chronic disorders. This is especially relevant in mental disorders. Treatment of chronic disorders requires a complex and multidisciplinary long-term-treatment which is regularly done by general practitioners. However, concepts for rehabilitation-medicine in outpatient settings are until now by and large insufficient.

METHODS

40 general practitioners were asked to give an estimate on how many patients with chronic psychological disorders were among their patients.Next, 1 451 patients between 18 and 60 years filled in the WHO-5 wellbeing-rating, the IMET scale on participation disorders, the Burvill scale on multimorbidity and answered questions on their mental and work status.

RESULTS

The general practitioners estimated that on average 41,9% (SD=18,2; Range 15-90%) were suffering from chronic mental disorders. 46,5% of the patients said that they suffered from mental problems, 38,3% had mental problems longer than 6 months, i. e., chronic, and in 26,9% even persistent. 29,7% of the patients suffered from chronic mental problems with relevant participation disorders.

CONCLUSION

Patients with chronic mental disorders and participation problems are frequent in general practice. Rehabilitation medicine is an important part the daily activities of general practitioners, including diagnosis, treatment, treatment coordination, and sociomedical interventions like sick leave certificates, or initiating inpatient rehabilitation. General practitioners should get more scientific attention when concepts of rehabilitation are discussed.

Cost of reproduction and covariation of life history traits in birds

Evolution of life history traits can be studied at two different levels: (1) current selection processes, including trade-offs in life history traits in natural populations as revealed by observations or, preferably, exieriments; and (2) patterns of variation in life history traits with each other and with ecology among extant species. Selection is not evolution, but selection pressures must have caused evolutionary change and led to current patterns of life history traits. These problems are exemplified by recent research on clutch size in birds.

Self-directed deliberate practice with virtual fiberoptic intubation improves initial skills for anesthesia residents

BACKGROUND

Fiberoptic intubation is a core skill in anesthesiology. However, this complex psychomotor skill is challenging to learn in the clinical setting. The goal of this study was to evaluate the Virtual Fiberoptic Intubation (VFI) software as an adjunct to the traditional fibreoptic intubation teaching.

METHODS

After informed consent, 23 first year anesthesia residents with no previous experience of fiberoptic intubation were randomized to 2 groups. All subjects received an institutional didactic teaching session. The control group (N.=12) was taught by the usual didactic method only, while the VFI group (N.=11) had the same didactic teaching and also the opportunity to practice with VFI software for one week. Each resident was evaluated on their first oro- and nasotracheal fiberoptic intubations on a mannequin head. Each performance was evaluated by an expert bronchoscopist blinded to the previous type of teaching using a checklist score, a global rating scale (GRS) score and procedural time.

RESULTS

The VFI group performed significantly better on the checklist and GRS scores compared to the control group for both the oral and nasal routes (all P<0.05). For procedural time, there was a trend towards faster performance in the VFI group compared to the control group for the oral route (P=0.05). There was no significant difference for procedural time between the VFI and the control groups when fiberoptic intubation was performed nasally (P=0.76).

CONCLUSION

Self-directed practice using VFI software may improve the initial acquisition of fibreoptic intubation skills for anesthesia residents.

Vitamin D deficiency in septic patients at ICU admission is not a mortality predictor

BACKGROUND

Vitamin D is involved in immune regulation in humans. Vitamin D serum deficiency is reported to be common in hospitalized patients, especially among Intensive Care Unit (ICU) patients. Our aim was to evaluate the relationship between vitamin D levels in septic patients and outcome.

METHODS

A total of 170 patients were studied, of which 92 were severe sepsis/septic shock patients, and 72 were major trauma patients, as an age-matched control group. Exclusion criteria were: age <18 years (y), malnutrition state, pregnancy, breast feeding, chemotherapy, immunotherapy, pathologies affecting bone and calcium metabolism, vitamin D metabolism derangement for therapy, hematological and solid malignancies, and HIV. Vitamin D levels were measured by radioimmunoassay at admission.

RESULTS

Median vitamin D levels at admission to ICU were 10.1 ng/mL in the sepsis group and 18.4 ng/mL in the trauma group (P<0.0001). In univariate analysis, mortality rate in septic patients was significantly correlated with age, gender, SAPS II, vitamin D level at admission, duration of mechanical ventilation, and ICU/hospital length of stay, however, the multivariate logistic regression model confirmed significance only for age.

CONCLUSION

In our cohort, septic patients showed a significantly lower vitamin D level than trauma patients in comparison to age cohort patients with the same demographic/clinical characteristics, but no clear relationship between vitamin D level and outcome was found. Further studies with larger samples are needed to clarify the prognostic role of vitamin D and nutraceutical interventions in critically ill patients.