Engineered Surfaces That Promote Capture of Latent Proteins to Facilitate Integrin-Mediated Mechanical Activation of Growth Factors

Conventional osteogenic platforms utilize active growth factors to repair bone defects that are extensive in size, but they can adversely affect patient health. Here, an unconventional osteogenic platform is reported that functions by promoting capture of inactive osteogenic growth factor molecules to the site of cell growth for subsequent integrin-mediated activation, using a recombinant fragment of latent transforming growth factor beta-binding protein-1 (rLTBP1). It is shown that rLTBP1 binds to the growth-factor- and integrin-binding domains of fibronectin on poly(ethyl acrylate) surfaces, which immobilizes rLTBP1 and promotes the binding of latency associated peptide (LAP), within which inactive transforming growth factor beta 1 (TGF-β1) is bound. rLTBP1 facilitates the interaction of LAP with integrin β1 and the subsequent mechanically driven release of TGF-β1 to stimulate canonical TGF-β1 signaling, activating osteogenic marker expression in vitro and complete regeneration of a critical-sized bone defect in vivo.

An engineered periosteum for efficient delivery of rhBMP-2 and mesenchymal progenitor cells during bone regeneration

During bone regeneration, the periosteum acts as a carrier for key regenerative cues, delivering osteochondroprogenitor cells and crucial growth factors to the injured bone. We developed a biocompatible, 3D polycaprolactone (PCL) melt electro-written membrane to act as a mimetic periosteum. Poly (ethyl acrylate) coating of the PCL membrane allowed functionalization, mediated by fibronectin and low dose recombinant human BMP-2 (rhBMP-2) (10-25 μg/ml), resulting in efficient, sustained osteoinduction in vitro. In vivo, rhBMP-2 functionalized mimetic periosteum demonstrated regenerative potential in the treatment of rat critical-size femoral defects with highly efficient healing and functional recovery (80%-93%). Mimetic periosteum has also proven to be efficient for cell delivery, as observed through the migration of transplanted periosteum-derived mesenchymal cells to the bone defect and their survival. Ultimately, mimetic periosteum demonstrated its ability to deliver key stem cells and morphogens to an injured site, exposing a therapeutic and translational potential in vivo when combined with unprecedentedly low rhBMP-2 doses.

Surface-Modified Piezoelectric Copolymer Poly(vinylidene fluoride-trifluoroethylene) Supporting Physiological Extracellular Matrixes to Enhance Mesenchymal Stem Cell Adhesion for Nanoscale Mechanical Stimulation

There is an unmet clinical need to provide viable bone grafts for clinical use. Autologous bone, one of the most commonly transplanted tissues, is often used but is associated with donor site morbidity. Tissue engineering strategies to differentiate an autologous cell source, such as mesenchymal stromal cells (MSCs), into a potential bone-graft material could help to fulfill clinical demand. However, osteogenesis of MSCs can typically require long culture periods that are impractical in a clinical setting and can lead to significant cost. Investigation into strategies that optimize cell production is essential. Here, we use the piezoelectric copolymer poly(vinylidene fluoride-trifluoroethylene) (PVDF-TrFE), functionalized with a poly(ethyl acrylate) (PEA) coating that drives fibronectin network formation, to enhance MSC adhesion and to present growth factors in the solid phase. Dynamic electrical cues are then incorporated, via a nanovibrational bioreactor, and the MSC response to electromechanical stimulation is investigated.

Impacts of Cognitive Factors on Creativity Quality in Design: Identification from Performances in Recall, Association and Combination

The reason why people have different creativity quality levels may depend on their different performances relating to other cognitive factors that are important for creativity. This study was designed to identify the performance of three cognitive factors (recall, association, and combination) that a designer may use in a creative process and then identify how the differing performance for these cognitive factors will affect creativity quality levels. Seventy-one participants were recruited to undertake a design task and complete a semi-structured interview. The results indicate that, in a creative design process, similar performances in recall, association, and combination can result in differences in creativity quality level.

WikiLink: An Encyclopedia-Based Semantic Network for Design Creativity

Data-driven design is a process to reuse data sources and provide valuable information to provoke creative ideas in the stages of design. However, existing semantic networks for design creativity are built on data sources restricted to technological and scientific information. Existing studies build the edges of a semantic network on statistical or semantic relationships, which are less likely to make full use of the benefits from both types of relationships and discover implicit knowledge for design creativity. Therefore, to overcome the gaps, we constructed WikiLink, a semantic network based on Wikipedia, which is an integrated source of general knowledge and specific knowledge, with broad coverage of disciplines. The weight in WikiLink fuses both the statistic and semantic weights between concepts instead of simply one type of weight, and four algorithms are developed for inspiring new ideas. Evaluation experiments are undertaken, and the results show that the network is characterised by high coverage of terms, relationships and disciplines, which demonstrates and supports the network's effectiveness and usefulness. A demonstration and case study results indicate that WikiLink can serve as an idea generation tool for creativity in conceptual design. The source code of WikiLink and the backend data are provided open-source for more users to explore and develop.

The Creativity Diamond—A Framework to Aid Creativity

There are many facets to creativity, and the topic has a profound impact on society. Substantial and sustained study on creativity has been undertaken, and much is now known about the fundamentals and how creativity can be augmented. To draw these elements together, a framework was developed called the creativity diamond, formulated on the basis of reviews of prior work, as well as the consideration of 20 PhD studies on the topics of creativity, design, innovation, and product development. The framework embodies the principles that quantity of ideas breeds quality through selection, and that a range of creativity tools can provoke additional ideas to augment our innate creativity. The creativity diamond proposed is a tool consisting of a divergent phase associated with the development of many distinctive ideas and a convergent phase associated with the refinement of ideas. The creativity diamond framework can be used to prompt and help select which tool or approach to use in a creative environment for innovative tasks. The framework has now been used by many students and professionals in diverse contexts.

Materials-driven fibronectin assembly on nanoscale topography enhances mesenchymal stem cell adhesion, protecting cells from bacterial virulence factors and preventing biofilm formation

Post-operative infection is a major complication in patients recovering from orthopaedic surgery. As such, there is a clinical need to develop biomaterials for use in regenerative surgery that can promote mesenchymal stem cell (MSC) osteospecific differentiation and that can prevent infection caused by biofilm-forming pathogens. Nanotopographical approaches to pathogen control are being identified, including in orthopaedic materials such as titanium and its alloys. These topographies use high aspect ratio nanospikes or nanowires to prevent bacterial adhesion but these features also significantly reduce MSC adhesion and activity. Here, we use a poly (ethyl acrylate) (PEA) polymer coating on titanium nanowires to spontaneously organise fibronectin (FN) and to deliver bone morphogenetic protein 2 (BMP2) to enhance MSC adhesion and osteospecific signalling. Using a novel MSC-Pseudomonas aeruginosa co-culture, we show that the coated nanotopographies protect MSCs from cytotoxic quorum sensing and signalling molecules, enhance MSC adhesion and osteoblast differentiation and reduce biofilm formation. We conclude that the PEA polymer-coated nanotopography can both support MSCs and prevent pathogens from adhering to a biomaterial surface, thus protecting from biofilm formation and bacterial infection, and supporting osteogenic repair.

Nanovibrational Stimulation of Mesenchymal Stem Cells Induces Therapeutic Reactive Oxygen Species and Inflammation for Three-Dimensional Bone Tissue Engineering

There is a pressing clinical need to develop cell-based bone therapies due to a lack of viable, autologous bone grafts and a growing demand for bone grafts in musculoskeletal surgery. Such therapies can be tissue engineered and cellular, such as osteoblasts, combined with a material scaffold. Because mesenchymal stem cells (MSCs) are both available and fast growing compared to mature osteoblasts, therapies that utilize these progenitor cells are particularly promising. We have developed a nanovibrational bioreactor that can convert MSCs into bone-forming osteoblasts in two- and three-dimensional, but the mechanisms involved in this osteoinduction process remain unclear. Here, to elucidate this mechanism, we use increasing vibrational amplitude, from 30 nm (N30) to 90 nm (N90) amplitudes at 1000 Hz and assess MSC metabolite, gene, and protein changes. These approaches reveal that dose-dependent changes occur in MSCs' responses to increased vibrational amplitude, particularly in adhesion and mechanosensitive ion channel expression and that energetic metabolic pathways are activated, leading to low-level reactive oxygen species (ROS) production and to low-level inflammation as well as to ROS- and inflammation-balancing pathways. These events are analogous to those that occur in the natural bone-healing processes. We have also developed a tissue engineered MSC-laden scaffold designed using cells' mechanical memory, driven by the stronger N90 stimulation. These mechanistic insights and cell-scaffold design are underpinned by a process that is free of inductive chemicals.

Nanoscale Coatings for Ultralow Dose BMP-2-Driven Regeneration of Critical-Sized Bone Defects

While new biomaterials for regenerative therapies are being reported in the literature, clinical translation is slow. Some existing regenerative approaches rely on high doses of growth factors, such as bone morphogenetic protein-2 (BMP-2) in bone regeneration, which can cause serious side effects. An ultralow-dose growth factor technology is described yielding high bioactivity based on a simple polymer, poly(ethyl acrylate) (PEA), and mechanisms to drive stem cell differentiation and bone regeneration in a critical-sized murine defect model with translation to a clinical veterinary setting are reported. This material-based technology triggers spontaneous fibronectin organization and stimulates growth factor signalling, enabling synergistic integrin and BMP-2 receptor activation in mesenchymal stem cells. To translate this technology, plasma-polymerized PEA is used on 2D and 3D substrates to enhance cell signalling in vitro, showing the complete healing of a critical-sized bone injury in mice in vivo. Efficacy is demonstrated in a Münsterländer dog with a nonhealing humerus fracture, establishing the clinical translation of advanced ultralow-dose growth factor treatment.

Failure to produce improvement in ECT documentation

A previous survey carried out in our unit revealed deficiencies in electroconvulsive therapy (ECT) documentation. With the aim of correcting these deficiencies, the standard procedure for completing the audit cycle was followed and the survey was repeated. The results question the assumption that simply completing the audit cycle ‘automatically’ leads to an improvement in practice. Possible reasons why Improvement did not come about in this study are discussed.

Clinical audit effects a reduction in routine prescribing of benzodiazepine hypnotics

The Edith Morgan Centre is a 60-bedded acute psychiatric in-patient unit on a DGH site, now open for three and a half years, following the closure of a nearby psychiatric hospital.

Nanoscale stimulation of osteoblastogenesis from mesenchymal stem cells: nanotopography and nanokicking

AIM

Mesenchymal stem cells (MSCs) have large regenerative potential to replace damaged cells from several tissues along the mesodermal lineage. The potency of these cells promises to change the longer term prognosis for many degenerative conditions currently suffered by our aging population. We have endeavored to demonstrate our ability to induce osteoblatogenesis in MSCs using high-frequency (1000-5000 Hz) piezo-driven nanodisplacements (16-30 nm displacements) in a vertical direction.

MATERIALS & METHODS

Osteoblastogenesis has been determined by the upregulation of osteoblasic genes such as osteonectin (ONN), RUNX2 and Osterix, assessed via quantitative real-time PCR; the increase of osteocalcin (OCN) and osteopontin (OPN) at the protein level and the deposition of calcium phosphate determined by histological staining.

RESULTS

Intriguingly, we have observed a relationship between nanotopography and piezo-stimulated mechanotransduction and possibly see evidence of two differing osteogenic mechanisms at work. These data provide confidence in nanomechanotransduction for stem cell differentiation without dependence on soluble factors and complex chemistries.

CONCLUSION

In the future it is envisaged that this technology may have beneficial therapeutic applications in the healthcare industry, for conditions whose overall phenotype maybe characterized by weak or damaged bones (e.g., osteoporosis and bone fractures), and which can benefit from having an increased number of osteoblastic cells in vivo.

Variability of bladder filling in patients receiving radical radiotherapy to the prostate

BACKGROUND AND PURPOSE

Patients receiving radical radiotherapy to the prostate are requested to maintain a full bladder to displace the dome of the bladder and small bowel from the target volume. This study investigated patients' ability to consistently maintain a full bladder throughout planning and treatment before (Study 1) and after (Study 2) the introduction of a patient information sheet.

PATIENTS AND METHODS

Bladder volumes were measured on 41 patients at CT scanning, simulation and once weekly during treatment using a portable ultrasound device, BladderScan BVI 3000. Patients were asked their assessment of bladder fullness, time since last urination and the volume of fluid drank. A patient information sheet on bladder filling was then introduced and the study repeated on 25 patients (Study 2). The ultrasound bladder volumes measured at CT were compared to the CT scan data.

RESULTS

There was a strong correlation between the ultrasound and CT bladder volumes r = 0.88 (P < 0.01). There was a significant decrease between the volume at CT (mean 362 ml, SD 229 ml) and treatment (mean 251 ml, SD 171 ml) in Study 1 (P = 0.002). In Study 2 the mean volume at CT was 286 ml (SD 164 ml) compared to a mean of 312 ml (SD 196 ml) during treatment. The measured volume correlated with patient self-assessment (r = 0.47, P < 0.01). The median volume drank by patients in Study 2 was 350 ml (range 50-825 ml) compared to 450 ml (range 75-1500 ml) in Study 1.

CONCLUSIONS

Our initial results showed patients were unable to maintain a constant bladder volume during planning and treatment. Implementation of written bladder filling instructions was shown to improve bladder volume consistency.

The use of gel dosimetry for verification of electron and photon treatment plans in carcinoma of the scalp

In recent years there has been a large amount of research into the potential use of radiation sensitive gels for three-dimensional verification of clinical radiotherapy doses. In this paper we report the use of a MAGIC gel dosimeter (Fong et al 2001 Phys. Med. Biol. 46 3105) for the verification of a specific patient's radiation therapy dose distribution. A 69-year-old male patient presented with a squamous cell carcinoma extending approximately 180 degrees across the top of the scalp (anterior to posterior) and from just over midline to 90 degrees left of the skull. The patient's treatment was commenced using two electron fields. For gel dosimetry, phantoms were produced in which the outer surface spatially corresponded to the outer contours of the patient's anatomy in the region of irradiation. The phantoms were treated with either electrons or intensity modulated radiation therapy (IMRT) with photons. The results identified a hot spot between the matched electron fields and confirmed the more homogeneous dose distribution produced by the IMRT planning system. The IMRT plan was then clinically implemented. The application of a clinical dose to a phantom shaped to a specific patient as well as the ability to select a slice at will during phantom imaging means that gel dosimetry can no longer be considered to simply have potential alone, but is now in fact a useful dosimetric tool.

Voice gains following thyroplasty may improve over time

Type I thyroplasty for unilateral vocal fold paralysis restores voice. The purpose of this study was to evaluate measures of voice before thyroplasty, and at 3 months and 1 year after surgery. Of interest was whether vocal improvement in the first weeks after surgery was maintained or even enhanced over time. A total of 40 patients with unilateral paralysis underwent type I thyroplasty with or without arytenoid adduction. Perceptual, acoustic and aerodynamic measures of voice were studied. Perceptual analysis determined that optimal postoperative voice quality evolved over the first year. Acoustic indices of perturbation demonstrated progressive improvement over 12 months, whereas pitch and intensity ranges were increasingly extended. Postoperative glottal flow rates were normalized and phonation times were significantly longer, with benefits maintained over time. All perceptual, aerodynamic and acoustic measures of voice were improved 3 months after thyroplasty, with many measures further improved at 1 year. Such findings provide evidence that voice outcome progressively evolves over the first 12 months after surgery.

Voice outcome following lateral laryngotomy to remove teflon granuloma

Formation of a Teflon granuloma may lead to progressive dysphonia and airway compromise. Excision of the granuloma by lateral laryngotomy allows preservation of the uninvolved lamina propria. A sternothyroid muscle flap or Silastic implant to medialize the vocal fold restores a straight glottal edge and optimizes voice production. Fifteen patients underwent removal of a Teflon granuloma via a lateral approach. Analysis of data revealed improved acoustic and aerodynamic parameters of voice following surgery. Indices of acoustic perturbation were reduced, and vocal pitch normalized. While the dynamic pitch range was unchanged, the capacity to vary loudness was enhanced. Flow rates in speech, abnormally elevated before surgery, normalized after the procedure, and phonation times were significantly longer. Perceptual and stroboscopic data confirmed that voices were improved, but not normal.

Ultrasound-modulated twin-fluid atomization of a liquid jet

A resonant liquid capillary wave theory which extends Taylor's dispersion relation to include the sheltering effect of liquid surface inclination caused by air flow is presented. The resulting dispersion curves are compared to new experimental results of how drop-size and size distributions vary with surface tension and air velocity in both airblast and ultrasound-modulated twin-fluid atomization of liquids with a constant kinematic viscosity of 2 cSt. Good agreements between the theoretical predictions of relative growth rates of the capillary waves and the experimental results of drop-size and size distributions led to the conclusion that Taylor-mode breakup of capillary waves plays a very important role in twin-fluid (airblast) atomization of a liquid jet. Thus, the ultrasound-modulated twin-fluid atomization not only verifies the capillary wave mechanism but also provides a means for controlling the drop-size and size distributions in twin-fluid atomization, which has a variety of applications in fuel combustion, spray drying, and spray coating.

A quality assurance procedure for the Varian multi-leaf collimator

A quick, simple set of tests has been devised to assess and record the quality assurance aspects of the Varian multi-leaf collimator (MLC) when used for clinical treatments on a regular basis. Pre-treatment, daily and weekly checks are performed by the radiographers while more detailed quality assurance is carried out at monthly and quarterly intervals by physicists.

Carotid body tumors: a review of 30 patients with 46 tumors

Minimal morbidity occurs with resection of most carotid body tumors (CBT). With larger tumors significant injury to the cranial nerves has been reported. In order to assess the operative sequelae rate, 30 patients with CBT were reviewed. Sixteen patients either presented with bilateral carotid body tumors or had previously undergone a resection of the contralateral carotid body tumors, for a total carotid body tumor count of 46. Sixteen patients demonstrated a familial pattern while 14 were nonfamilial. Within the familial group, 14 of 16 presented with multiple paragangliomas as compared to 6 of 14 in the nonfamilial group. Tumor size ranged from 0.8 to 12 cm. Vascular replacement occurred in 2 of 20 patients with tumors < 5.0 cm, compared with 5 of 9 with tumors > 5.0 cm. Four patients lost cranial nerves with the resection: superior laryngeal nerve (SLN), 4; cranial nerve X, 1; cranial nerve XII, 1. Ten patients developed baroreceptor failure secondary to bilateral loss of carotid sinus function. First-bite pain occurred in 10 of 25 operative patients. Cranial nerve loss can be minimal with resection of carotid body tumors, however, baroreceptor failure and first-bite pain are postoperative sequelae that are often disregarded in the postoperative period.

The effect of temazepam on melatonin secretion and light sensitivity

Seven healthy male volunteers had their light sensitivity (melatonin suppression) and melatonin phase measured before and after treatment with temazepam (20 mg) for 7 days. Temazepam did not alter the circadian phase of melatonin secretion (the Dim Light Melatonin Onset, the timing of the peak of secretion), the total melatonin secretion nor the sensitivity of melatonin secretion to suppression by full spectrum light. This is an important negative finding which suggests that the short half-life benzodiazepine hypnotic temazepam does not confound tests of light sensitivity or melatonin phase.

Peptic ulcer, pyloroplasty, and dietary fat. A new concept

The hypothesis that peptic ulcer is a manifestation of a generalized metabolic disorder caused by excess dietary fat intake is supported by the results in a series of 134 patients with proven gastric or duodenal ulcer treated with a simple 'fat-free' diet, together with pyloroplasty in 82 cases and simple suture of a perforated ulcer in 16. Relief of symptoms and healing of the ulcer resulted in the great majority of cases so long as the diet was strictly adhered to, and there have been no side effects or morbidity.

A new look at diarrhoea, diverticulitis and 'colitis' after 25 years of clinical study

The clinical features of fat-intolerant bowel disturbance, which have been established by study, over a period of 25 years, of bowel disturbance seen in dyspeptic and other patients, are described. Excess dietary fat intake is an etiological factor in the irritable colon syndrome, spastic colon, diverticulosis, and diverticulitis of the colon and in ulcerative and non-ulcerative colitis. All these conditions are manifestations of intolerance to excess dietary fat intake, and are controlled, and their symptoms are cured, by adherence to the fat-free diet: i.e. a diet from which is excluded any fat derived from cow's milk, from the pig, any 'store' or 'depot' fat, and any vegetable fat concentrate.

Dietary fat, dyspepsia, diarrhoea, and diabetes

This paper postulates that fat intolerance is a widespread metabolic disorder characterized by impairment of glucose tolerance caused by excess dietary fat intake, and cured in most cases by the fat-free diet as defined in this paper.

Fat intolerance may present as flatulent dyspepsia, surgical disease or disorder in the biliary tract, peptic ulcertion, diarrhoea associated with spasm or diverticular disease of the colon or colitis, or as maturity-onset diabetes mellitus; one, two, or more of these syndromes may occur at the same or different times in the same patient. The dietary fat intake and the effect of the fat-free diet in each of these syndromes have been investigated, and the findings and their implications are discussed.

Treatment of disease and disorder in the biliary tract by sphincterotomy of the sphincter of Oddi in a series of 57 cases and of duodenal ulcer by pyloroplasty alone in 50 cases is reported. The results of treatment of duodenal ulcer by pyloroplasty alone in a series of 38 cases are compared with those after vagotomy and pyloroplasty in a similar series of 38 cases. Cure of peptic ulceration by pyloroplasty alone is reported, and vagotomy is considered to be unnecessary. The normal pylorus is defined, and the naked-eye appearances of the pylorus observed during 87 cholecystectomies are reported. The significance of these observations and of radiological abnormalities seen in routine barium-meal examinations of cases of disease or disorder in the biliary tract is discussed. Evidence is presented that the function of and pathological changes in the sphincter of Oddi and the pylorus are affected by the dietary fat intake and determine the absence or presence of abnormality in the biliary tract or of peptic ulceration respectively.

The clinical syndromes of fat-intolerant diarrhoea and its association with spasm of the colon, colitis, and diverticulitis, and of abdominal pain due to fat intolerance seen in a series of 17 children, are described as clinical entities.

The effect of the fat-free diet on glucose tolerance has been investigated in a series of 65 patients, and the significance of the increased tolerance observed has been assessed statistically. Four hundred and thirty-three glucose-tolerance tests have been performed to assess the change in glucose tolerance in 134 patients who had been on the fat-free diet for periods of 3 months to 2 years as treatment for dyspepsia due to disease or disorder of the biliary tract, peptic ulceration, diarrhoea associated with spasm of the colon, diverticulitis or colitis, obesity, and migraine. Among these patients were 23 who also suffered from diabetes mellitus. Cure of maturityonset diabetes mellitus by the fat-free diet is reported, and evidence is produced to show that it is an acquired abnormality of the metabolism caused by excess dietary fat intake.