Microfluidic device-fabricated spiky nano-burflower shape gold nanomaterials facilitate large biomolecule delivery into cells using infrared light pulses

Photothermal nanoparticle-sensitised photoporation is an emerging approach, which is considered an efficient tool for the intracellular delivery of biomolecules. Nevertheless, using this method to achieve high transfection efficiency generally compromises cell viability and uneven distribution of nanoparticles results in non-uniform delivery. Here, we show that high aspect ratio gold nano-burflowers, synthesised in a microfluidic device, facilitate highly efficient small to very-large cargo delivery uniformly using infrared light pulses without sacrificing cell viability. By precisely controlling the flow rates of shaping reagent and reducing agent, high-density (24 numbers) sharply branched spikes (∼80 nm tip-to-tip length) of higher aspect ratios (∼6.5) with a small core diameter (∼45 nm) were synthesised. As produced gold burflower-shape nanoparticles are biocompatible, colloidally stable (large surface zeta potential value), and uniform in morphology with a higher plasmonic peak (max. 890 nm). Theoretical analysis revealed that spikes on the nanoparticles generate a higher electromagnetic field enhancement upon interaction with light pulses. It induces plasmonic nanobubbles in the vicinity of the cells, followed by pore formation on the membrane leading to diverse biomolecular delivery into cells. Our platform has been successfully implemented for uniform delivery of small to very large biomolecules, including siRNA (20-24 bp), plasmid DNA expressing green fluorescent protein (6.2 kbp), Cas-9 plasmid (9.3 kbp), and β-galactosidase enzyme (465 kDa) into diverse mammalian cells with high transfection efficiency and cell viability. For very large biomolecules such as enzymes, the best results were achieved as ∼100% transfection efficiency and ∼100% cell viability in SiHa cells. Together, our findings demonstrate that the spiky gold nano-burflower shape nanoparticles manufactured in a microfluidic system exhibited excellent plasmonic behaviour and could serve as an effective tool in manipulating cell physiology.

Neuromodulation of spinal reflex pathway for the treatment of detrusor overactivity by medial plantar nerve stimulation at surface of sole of foot in patients with spinal cord injury

Objectives

Suprasacral spinal cord lesions are prone to have neurogenic detrusor overactivity leading to urinary incontinence. Current medical management has known side-effects and often surgical managements are irreversible. Electrical stimulation to modulate spinal reflex pathway having same nerve root as urinary bladder is reported in the literature. This study aimed to reduce detrusor overactivity in patients with spinal cord injury (SCI) using surface electrical stimulation of medial plantar nerve at the sole of foot.

Materials and Methods

Twenty adults with SCI having episode of at least 1 leak/day due to detrusor overactivity as diagnosed by cystometrogram (CMG), were on clean intermittent catheterization and ankle jerk was present consented for the study. Participants were asked to maintain bladder diary a week before and during 2 weeks of treatment. CMG was done on day-0 and day-14. cmcUroModul@tor®, an inhouse developed electrical stimulator was used for ½ h daily for period of 2 weeks. Patient satisfaction feedback questionnaire was taken on completion of treatment. CMG data were analyzed using Wilcoxon signed-ranked test while bladder diary was analyzed using binomial distribution. P < 0.05 was considered as statistically significant. Institutional Review Board (IRB) and ethics committee of Christian Medical College, Vellore, approved the study (CMC/IRB/11061).

Results

Statistical significant improvement in maximum detrusor pressure (P = 0.03) and cystometric capacity (P = 0.04) was observed. Of 20 subjects, 18 showed improvement in bladder diary.

Conclusion

Neuromodulation of medial plantar nerve at sole of foot by surface electrical stimulation is non-invasive, cost-effective, and alternative simple treatment modality for urinary incontinence due to detrusor overactivity.

Ankle dorsiflexion assist using a single sensor-based FES: Results from clinical study on patients with stroke

Objective

Ankle foot orthosis (AFO) commonly prescribed to manage foot-drop following stroke restricts ankle mobility. Commercially available functional electrical stimulation (FES) is an expensive alternative to achieve desired dorsiflexion during swing phase of the gait cycle. An in-house cost-effective innovative solution was designed and developed to address this problem.The aim of the study was to compare spatiotemporal gait characteristics of patients with foot-drop following stroke using commercially available FES against in-house developed versatile single sensor-based FES.

Material and Methods

Ten patients with cerebrovascular accident of at least 3 months duration and ambulant with/without AFO were recruited prospectively. They were trained with Device-1 (Commercial Device) and Device-2 (In-house developed, Re-Lift) for 7 h over 3 consecutive days with each device. Outcome measures included timed-up-and-go-test (TUG), six-minute-walk-test (6MWT), ten-meter-walk-test (10MWT), physiological cost index (PCI), instrumented gait analysis derived spatiotemporal parameters, and patient satisfaction feedback questionnaire. We calculated intraclass correlation between devices and median interquartile range. Statistical analysis included Wilcoxon-signed-rank-test and F-test (P < 0.05 was considered statistically significant). Bland Altman and scatter plots were plotted for both devices.

Results

Intraclass correlation coefficient for 6MWT (0.96), 10MWT (0.97), TUG test (0.99), and PCI (0.88) reflected high agreement between the two devices. Scatter plot and Bland Altman plots for the outcome parameters showed good correlation between two FES devices. Patient satisfaction scores were equal for both Device-1 and Device-2. There was statistically significant change in swing phase ankle dorsiflexion.

Conclusions

The study demonstrated good correlation between commercial FES and Re-Lift suggestive of the utility of low-cost FES device in clinical setting.

Swing phase considerations in prosthetic knee design: Case series to validate simulations

BACKGROUND

Previously reported simulations comparing a new polycentric knee (called IPK) and a single-axis knee suggested that polycentricity could lead to improved performance during swing phase and negate the need for an extension assist. They also showed that an anteriorly translated socket adapter for enhanced stance stability compromises foot clearance during swing.

OBJECTIVES

The objectives of this study are to validate those findings using gait trials to enable further improvement in the IPK design before mass production.

METHODS

Three subjects regularly using three different passive knees, single-axis knee without extension assist, single-axis knee with extension assist (SAK-EA), and polycentric knee with extension assist (Mobility India-sourced polycentric knee), participated in this study. Their gait with their regular prosthesis and with IPK (having no extension assist) were analyzed, compared, and broadly correlated with simulation results.

RESULTS

Extension assist in single-axis knee with extension assist improved swing performance, affected foot clearance in Mobility India-sourced polycentric knee, and was found to be unnecessary in the IPK. With an anteriorly placed socket adapter in the IPK, compensatory strategies were necessary for foot clearance. The IPK was found to provide better knee extension characteristics with lower hip effort (up to 42% reduction) than other knees.

CONCLUSIONS

This case series confirmed previously reported simulation results on the swing phase behavior of passive prosthetic knees. The performance of the IPK during swing obviated the need for an extension assist, thereby simplifying the design. Appropriate design changes in the IPK's socket adapter location are required to achieve both stance stability and reduce gait compensations for foot clearance.

Validation of wearable inertial sensor-based gait analysis system for measurement of spatiotemporal parameters and lower extremity joint kinematics in sagittal plane

Wearable inertial sensor-based motion analysis systems are promising alternatives to standard camera-based motion capture systems for the measurement of gait parameters and joint kinematics. These wearable sensors, unlike camera-based gold standard systems, find usefulness in outdoor natural environment along with confined indoor laboratory-based environment due to miniature size and wireless data transmission. This study reports validation of our developed (i-Sens) wearable motion analysis system against standard motion capture system. Gait analysis was performed at self-selected speed on non-disabled volunteers in indoor ( n = 15) and outdoor ( n = 8) environments. Two i-Sens units were placed at the level of knee and hip along with passive markers (for indoor study only) for simultaneous 3D motion capture using a motion capture system. Mean absolute percentage error (MAPE) was computed for spatiotemporal parameters from the i-Sens system versus the motion capture system as a true reference. Mean and standard deviation of kinematic data for a gait cycle were plotted for both systems against normative data. Joint kinematics data were analyzed to compute the root mean squared error (RMSE) and Pearson’s correlation coefficient. Kinematic plots indicate a high degree of accuracy of the i-Sens system with the reference system. Excellent positive correlation was observed between the two systems in terms of hip and knee joint angles (Indoor: hip 3.98° ± 1.03°, knee 6.48° ± 1.91°, Outdoor: hip 3.94° ± 0.78°, knee 5.82° ± 0.99°) with low RMSE. Reliability characteristics (defined using standard statistical thresholds of MAPE) of stride length, cadence, walking speed in both outdoor and indoor environment were well within the “Good” category. The i-Sens system has emerged as a potentially cost-effective, valid, accurate, and reliable alternative to expensive, standard motion capture systems for gait analysis. Further clinical trials using the i-Sens system are warranted on participants across different age groups.

Effect of dyslipidemia on intima-media thickness of intra- and extracranial atherosclerosis by regulating the expression of hsp70 in rabbits

The aim of this study was to explore the effect of dyslipidemia on intima-media thickness (IMT) of Intra- and extracranial atherosclerosis by regulating the expression of heat shock protein 70 (HSP70) in rabbits. Twenty-seven male white rabbits were randomly divided into normal control group A, high fat group B and high fat + endothelial injury operation group C (each group was 9), we measured lipids and obtained tissues from different cerebral arteries including Bilateral common carotid artery (CCA), Internal carotid artery (ICA), middle cerebral artery (MCA) and vertebral artery (VA). Pathological analysis were done, western blot analysis was used to detect the expression of HSP70 in CCA and MCA. The Serum lipid levels were overall significantly increased at 12(th) week in Group B and Group C compared to normal control (P < 0.05); at 12(th) week, the IMT of CCA and MCA in group B and C were showed significant increment compared with Group A; the correlation between HDL/CHOL/LDL and IMT of different cerebral arteries are as follows: MCA > ICA > CCA > VA; between TG and IMT of different cerebral arteries: VA > ICA > MCA > CCA; the expression of HSP70 from MCA were increased compared with CCA in group B and group C (P < 0.05). Significant positive correlations were observed between hyperlipidemia and different cerebral arteries. Hyperlipidemia has more impact on IMT of intracranial cerebral arteries. The expression of HSP70 from intracranial cerebral arteries is significantly increased. The mechanisms underlied was speculated that might be involved in inhibiting the inflammatory via HSP70.

Neuromodulation by surface electrical stimulation of peripheral nerves for reduction of detrusor overactivity in patients with spinal cord injury: A pilot study

OBJECTIVES

To demonstrate reduction in detrusor overactivity using surface electrical stimulation of posterior tibial nerve (PTN) or dorsal penile nerve (DPN) in patients with spinal cord injury (SCI).

DESIGN

Patients with SCI with symptoms of urinary urgency/leaks, with cystometrogram (CMG) proven detrusor overactivity were recruited in this study. Ten persons with observable F-wave from tibial nerve were included in the PTN group. Five persons who had F-wave absent but preserved bulbocavernosus reflex were included in the DPN group. Stimulation was given at 20 Hz, 10-40 mA for 20 minutes/session/day for 14 consecutive days. Detrusor overactivity was recorded using CMG on days 1 and 15.

SETTINGS

Rehabilitation Institute, Department of Physical Medicine and Rehabilitation, Christian Medical College and Hospital, Vellore, TN, India.

PARTICIPANTS

Patients with SCI.

INTERVENTIONS

Surface stimulation of peripheral nerves for reduction of detrusor overactivity.

OUTCOME MEASURES

Qualitative analysis using voiding diary data and quantitative analysis using CMG data comparing pre- and post-intervention.

RESULTS

P value obtained from voiding chart was 0.021 for PTN and 0.062 for DPN. P value obtained from CMG data was not significant in both groups. In one subject, treatment was extended to 4 weeks and further improvement in voiding diary was seen.

CONCLUSIONS

In this pilot study of 15 patients, voiding chart data showed statistically significant improvement following PTN stimulation and trend of improvement following DPN stimulation. However, the CMG data were not statistically significant in this sample population. Further studies with larger, appropriately powered sample size would be helpful to demonstrate the associations of symptoms with CMG data. Trial registration CTRI no.; CTRI/2012/12/003234; CMCH Approval no.: CMC/IRB/6735/2008/12/18.

Neonatal presentation of incontinentia pigmenti with a family history extending over four generations--a case report

We report a case of Incontinentia pigmenti (IP). A day 2 female presented to the special care nursery with seizures. EEG showed multifocal epileptiform discharges and cranial MRI revealed extensive cerebral infarction. A rash appeared shortly after birth. Eye examination revealed changes of IP. There is a strong family history of IP. Genetic testing excluded the most common mutation. Follow-up reveals significant development delay.

A palmar pressure sensor for measurement of upper limb weight bearing by the hands during transfers by paraplegics

Paraplegic patients have to effect transfer from one seat to another by using their upper limbs. In this process the hands bear almost the entire weight of the body in at least some phases of the transfer. It is desirable to train patients, especially those who are elderly and otherwise weak, to distribute their weight so as to avoid large forces being sustained on any one hand for an extended period. It is also desirable to evaluate the effectiveness of assistive devices like lower limb FES in sharing the load on the hand. This study presents a simple and versatile method of measuring palmar hand force during transfers by paraplegic patients. It is important that this force sensor should not interfere with the grasping and stabilizing properties of the hands and should permit normal transferring. The force sensor comprises an air-filled pouch or pillow that can be placed on any surface. This pneumatic sensor feels like upholstery padding on the surface on which it is placed. The sensor integrates the total pressure applied to the surface of the pouch, thereby obtaining the total force exerted by the palm/hand. The fabrication of the sensor is described, as well as the associated measurement circuit. The static calibration shows that the sensor is linear up to 350 N and the dynamic calibration shows that it has a bandwidth of 13 Hz. The sensor was fabricated using an inflated inelastic airbag attached to a pressure transducer. An automatic offset correction circuit in the preamplifier module ensures that any offset due to initial pressure or sensor drift is removed and the output is zero under no load condition. The key to this sensor arrangement is the ease of fitting it into the intended location without disturbing the existing arrangement for the subject's activities of daily living (ADL).

Platelet glycoprotein IaC807T polymorphisms and ischemic stroke in young Chinese Han population

OBJECTIVES

The objective of this study was to investigate the association between platelet glycoprotein (GP) Ia C807T polymorphisms and ischemic stroke in young Chinese Han Population.

MATERIALS AND METHODS

We conducted a case-control study in 92 consecutive young (</= 50 years) first-ever hospitalized ischemic stroke inpatients and outpatients, 86 elder ischemic stroke control (> 50 years), and 160 age- and sex-matched healthy control. Genotyping of platelet GP Ia C807Tpolymorphisms was performed by polymerase chain reaction followed by sequencing nucleic acid with dideoxy chain-termination method and an ABI PRISM3100 (Perkin-Elmer Co) genetic analyzer. Student's t-test, chi-square test, and logistic regression modeling were used for data significance analyses.

RESULTS

Hypertension and smoking were found to be the independent risk factors for ischemic stroke patients (aged </= 50 years), while hypertension, diabetes and smoking were the independent risk factors for ischemic stroke patients (aged > 50 years). There was no significant difference observed in the T allele frequency of GPIa C807T polymorphisms between young stroke patients and corresponding controls.

CONCLUSIONS

These findings suggest that there is no role of GPIa C807T polymorphisms in the development of young first-ever ischemic stroke in Chinese Han Population.

Hysteresis and packing in gas-fluidized beds

The packing fraction and the pressure drop across gas-fluidized beds of granular media exhibit hysteresis as the gas-flow rate is cycled up and down across the fluidization transition. Presumably this is due to contact forces and transfer of stress to the surrounding walls, and hence should vary nontrivially with the aspect ratio of the sample. Here we present systematic measurements of the variation of hysteresis with particle size and aspect ratio of the sample. Remarkably, the hysteresis scales in a trivial way with these parameters, showing no evidence of long-range effects of the wall. Our measurements also show that the packing fraction becomes 0. 590+/-0.004, independent of particle size and container shape, when the fluidizing flow of gas flow is slowly removed.