Gel Pad Research Articles

Automation Highlights from the Literature

Automation Highlights from the Literature

Use of RFID temperature monitoring to test and improve fish packing methods in styrofoam boxes

To fulfil the temperature requirements of the cold chain, the fresh fish are usually packed, stored and transported to fish markets with ice in open styrofoam boxes. Some companies offer a more flexible service and they deliver the fish directly to private consumers. In these cases the fish are packed with artificial ice – hydrated and frozen gel pads in specially designed completely closed styrofoam boxes. This study presents the results of the comparison of seven packing methods with the aim to potentially improve them. The temperature outside and inside of the closed box and temperatures in the abdominal cavity of gutted sea bass (Dicentrarchus labrax) were measured during the logistics process using Radio Frequency Identification (RFID) technology. The aim of the presented study is to define the optimal cooling materials and methods for different handling options. As an important result, a new efficient, time and energy saving method of packing the fish with the combination of dry non-hydrated gel pads and wet ice instead of the use of frozen gel pads alone is proposed. This method ensures recommended storage temperatures between 0°C and 4°C and stable conditions inside the box at room temperatures (or higher) for a longer period of time under the same time-ambient conditions after delivery to the consumer. Furthermore it was established that the part of the ice that melted inside the box, due to higher ambient temperatures, was absorbed by the dry gel pad and only a small quantity of water remained on the bottom of the box.

Preliminary field study on saddle pressure distribution in horses without back pain

Objective of the study was to assess saddle pressure distribution in a normal horse population and to determine whether or not the pressure pad used is able to provide reliable information on saddle fit in a field setting. In addition the influence of type of saddle, type of saddle pad and back conformation on saddle pressure distribution was investigated. Forty randomly sampled horses were equipped and measured with a pressure pad at rest, during free and medium (collected) walk and during rising and sitting trot. All measurements were made on the straight line and were summarized according to the percentage pressure distribution front to back, as well as left, right and middle (spinal), of the saddle. Additional data were collected by a questionnaire and all data were statistical analyzed by the program STS 3.42 and NCSS 2007 (ANOVA). Significantly higher percentage pressures were noted at the back of the saddle in horses with poor musculature in the lumbar region when compared with those with prominent muscles in this area. Measurements using alternative saddle pads such as gel pads, foam material pads or yoga mats were variable and gave significantly different (higher) percentage pressures when compared to the traditional thin textile saddle pad. Western saddles showed significantly higher percentage pressure distribution towards the front of the saddle while a treeless saddle showed a higher percentage pressure distribution over midline. This study provides preliminary information on the saddle pressure distribution in a normal horse population measured in the field setting. Larger numbers would enable more robust interpretation of pressure measurements and improve on their clinical relevance.

A Randomized Clinical Trial to evaluate the Effect of Therapeutic Ultrasound and Low-level Laser Therapy on Perineal Pain following Vaginal Delivery with Episiotomy

ABSTRACT Background and objectives Vaginal delivery has an enormous amount of pressure on the perineum, the area between vagina and anus, which must stretch to accommodate the baby's head during its passage through the birth canal. During childbirth, the perineum may tear or the obstetrician may decide to incise to make wider opening for baby's head to pass, a procedure called as episiotomy. The area of episiotomy may be uncomfortable and painful for several days. The present study aimed to evaluate the effect of therapeutic ultrasound and low-level laser therapy (LLLT) on perineal pain following vaginal delivery with episiotomy. Materials and methods Sixty women, who underwent vaginal delivery with episiotomy, complaining of perineal pain were recruited and randomly allocated to two treatment groups. Physiotherapy intervention included cryo gel pad and therapeutic ultrasound in group A and cryo gel pad and lowlevel laser therapy in group B once daily for 3 consecutive days. Outcomes Measures were documented using visual analog scale (VAS) for pain and REEDA scale (redness, edema, ecchymosis, discharge, approximation) for healing on 1st day preintervention and 3rd day postintervention respectively. Results The study results showed that there was statistically significant improvement postintervention in both the groups with p < 0.05, although therapeutic ultrasound with cryo gel pad showed better reduction in pain score and healing process as compared to low-level laser therapy. Conclusion Therapeutic ultrasound with cryo gel pad can be used to reduce perineal pain following vaginal delivery with episiotomy. How to cite this article Chougala A, Mahishale A. A Randomized Clinical Trial to evaluate the Effect of Therapeutic Ultrasound and Low-level Laser Therapy on Perineal Pain following Vaginal Delivery with Episiotomy. J South Asian Feder Obst Gynae 2015;7(3):152-156.

Electroacupuncture improves microcirculation and neuronal morphology in the spinal cord of a rat model of intervertebral disc extrusion.

Most studies on spinal cord neuronal injury have focused on spinal cord tissue histology and the expression of nerve cell damage and repair-related genes. The importance of the microcirculation is often ignored in spinal cord injury and repair research. Therefore, in this study, we established a rat model of intervertebral disc extrusion by inserting a silica gel pad into the left ventral surface of T13. Electroacupuncture was used to stimulate the bilateral Zusanli point (ST36) and Neiting point (ST44) for 14 days. Compared with control animals, blood flow in the first lumbar vertebra (L1) was noticeably increased in rats given electroacupuncture. Microvessel density in the T13 segment of the spinal cord was increased significantly as well. The number of normal neurons was higher in the ventral horn of the spinal cord. In addition, vacuolation in the white matter was lessened. No obvious glial cell proliferation was visible. Furthermore, hindlimb motor function was improved significantly. Collectively, our results suggest that electroacupuncture can improve neuronal morphology and microcirculation, and promote the recovery of neurological functions in a rat model of intervertebral disc extrusion.

Gel pad array chip for high throughput and multi-analyte microbead-based immunoassays

We present here a gel pad array chip for high-throughput and multi-analyte microbead-based immunoassays. The chip is fabricated by photo-patterning of two polymeric gels, polyacrylamide gel and polyethylene glycol (PEG) gel, on a glass slide. The resulting chip consists of 40 polyacrylamide gel pad array units for the immobilization of microbeads and each gel pad array is surrounded with a PEG micropillar ring to confine the samples within the microarray. As a proof of concept, this chip was tested for quantitative immunoassays for two model cancer markers, human chorionic gonadotropin (hCG) and prostate specific antigen (PSA), in serum samples. Detection limits below the physiological threshold level for cancer diagnosis were achieved with good inter- and intra-chip reproducibility. Moreover, by using spatial encoded microbeads, simultaneous detection of both hCG and PSA on each gel pad array is achieved with single filter fluorescence imaging. This gel pad array chip is easy to use, easy to fabricate with low cost materials and minimal equipment and reusable. It could be a useful tool for common biolabs to customize their own microbead array for multi-analyte immunoassays.

Macroscopic and histological investigation of guanaco footpads (Lama guanicoe, Müller 1776).

The surface of guanaco footpads is characterized by hairless skin with up to 4-mm-thick stratum corneum that protects from abrasion. The horny layer is pliable and elastic, and ensures firm contact with irregular ground. It is padded with a particular structure of the subcutaneous layer, the digital cushion. The flat cushions of each of the two digits are of elongated ovate shape, each about 45-mm long, up to 20-mm wide, and 8-mm thick. The cushions are lined by a 1-2-mm-thick capsule that resembles a tunica albuginea. The capsule consists of coarse collagen fibers, with elastic fibers absent. The cushion capsule and dermis approach each other, and fuse along a line that runs parallel to the longitudinal axes of cushion and digit. Loose connective tissue rich in elastic fibers and acidic glycosaminoglycans separates dermis and cushion capsule lateral to the narrow interconnecting zone. The cushion capsule encloses cloudy yellowish, gelatinous material. Microscopy shows bundles of elastic fibers in abundant mucinous matrix. Tightly gathered elastic bundles adjoin the inner surface of the capsule. Rough cords of elastic fibers branch out from there and traverse to the opposite side. The cushion is pressed flat, and elastic fibers are stretched when bearing weight. With relief of load, elastic fibers contract and reset the cushion's shape. Contractile cells are absent. A resistant capsule and easily malleable mucinous contents establish the functioning as a gel pad. Mucinous connective tissue between elastic fiber bundles contains abundant basophilic matrix. Hyaluronan, chondroitin sulfate, and dermatan sulfate are main matrix constituents. Spindle-shaped or stellate fibroblasts contain vimentin, S100 protein, and neuron specific enolase. Moprhology, staining characteristics and synthesis activities of these cells meet the criteria to be classified as myxoid cells. The connective tissue in guanaco digital cushions represents myxoid tissue.

Swim ring method—a cost-effective alternative for prevention and healing of back ulcers

Sir, Traumatic and pressure ulcers on the back are a challenging part of patient care in intensive care units. Decubitus ulcers on the back in bedridden and orthopedically immobilised patients pose a significant challenge to the treating doctor and add great economical burden to the health-care system. It is estimated that the incidence of pressure ulcers in hospitalised elderly patients in the institutions ranges from 3 to 30 % [1–3]. The basic pathogenesis is prolonged pressure loading, leading to decreased skin blood flow causing tissue hypoxia and ischaemia [1–4]. Relieving pressure from areas on and around the ulcer is one of the important aspects of the management of ulcers, especially on the back when the patient is bedridden [1–4]. Specialised support surfaces such as mattresses and cushions with static air, water and foam support have been tried for offloading the pressure. Patient compliance and cost play a key role in choosing the pressure redistribution devices in the treatment of such ulcers [2–5]. Swim rings, also called swimming tubes, are inflated with air to keep the swimmer afloat and are available in various sizes to fit children and adults. The cost of these tubes varies from $5 to $10 (70–150 in India) depending on quality and size. These tubes can effectively offload the pressure on the back ulcers and improve healing. Once the patients have undergone a regular dressing of the ulcers on the back, they are positioned supine in the bed with the swim ring beneath the lower back in such a way that the ulcer-bearing part of the buttock lies inside the inner circle (free area) of the ring and the outer rim engages the lower back, upper thigh and outer most part of the gluteal region (Fig. 1). Two more swim rings are kept, one underneath the head and shoulder and another beneath the legs to ensure that the entire body is at the same level with all three rings underneath for maximum patient comfort and compliance (Fig. 2). Swim rings help to keep around 50 % back area to be contact-free. Air pressure in the swim ring can be adjusted by inflating it with air enough to achieve compressibility of about 1.5–2 in. (half finger depth, ∼12–15 psi) by digital pressure to ensure that it acts as a cushion for the pressure points. Swim rings are checked daily for 1.5–2 in. indentation of the tube by digital pressure before putting the patient over them.A layer of gel pads or foam can be added between the rings and the patient’s body to prevent excoriation caused by contact of plastic with the skin and the interposing sweat and wound discharge. For frequent change of position to lateral side to prevent discomfort, the rings are removed before the postural changes. The tubes are disinfected daily. We have been using these swim rings in our intensive care units for the past 1 year for faster wound healing and to prevent development of new pressure ulcers (Fig. 3a, b). In our experience, the swim tube scores over the other methods of pressure offloading in terms of cost, patient acceptability, easy to use, clean, carry and replace. Informed consent was obtained from all individual participants included in the study. The swim ring has the following advantages:

High-resolution nanotransfer printing applicable to diverse surfaces via interface-targeted adhesion switching.

Nanotransfer printing technology offers outstanding simplicity and throughput in the fabrication of transistors, metamaterials, epidermal sensors and other emerging devices. Nevertheless, the development of a large-area sub-50 nm nanotransfer printing process has been hindered by fundamental reliability issues in the replication of high-resolution templates and in the release of generated nanostructures. Here we present a solvent-assisted nanotransfer printing technique based on high-fidelity replication of sub-20 nm patterns using a dual-functional bilayer polymer thin film. For uniform and fast release of nanostructures on diverse receiver surfaces, interface-specific adhesion control is realized by employing a polydimethylsiloxane gel pad as a solvent-emitting transfer medium, providing unusual printing capability even on biological surfaces such as human skin and fruit peels. Based on this principle, we also demonstrate reliable printing of high-density metallic nanostructures for non-destructive and rapid surface-enhanced Raman spectroscopy analyses and for hydrogen detection sensors with excellent responsiveness.

Phosphorus-based bifunctional organocatalysts for the addition of carbon dioxide and epoxides.

Bifunctional phosphonium salts were synthesized and employed as organocatalysts for the atom efficient synthesis of cyclic carbonates from CO2 and epoxides for the first time. These catalysts were obtained in high yields by a modular, straightforward one-step synthesis. The hydrogen-bond donating alcohol function in the side chain leads to a synergistic effect accelerating the catalytic reaction. The desired cyclic carbonates are obtained in high yields and selectivity under solvent-free reaction conditions without the use of any co-catalyst. Under optimized reaction conditions various epoxides were converted to the corresponding cyclic carbonates in excellent yields. The products were obtained analytically pure after simple filtration over a silica gel pad. This protocol is even applicable for a multigram reaction scale. Moreover, the catalysts could be easily recovered and reused up to five times.

Comprehensive Curriculum for Phantom-Based Training of Ultrasound-Guided Intercostal Nerve and Stellate Ganglion Blocks

Ultrasound (US)-guided pain procedures become increasingly important due to their numerous advantages. Solid proficiency is necessary, however, to minimize complications and guarantee adequate performance. To enable beginners to learn the relevant skills in the technique of US-guided stellate ganglion (SGB) and intercostal nerve block (ICB), a training curriculum was developed and tested using self-made phantoms. The curriculum comprised an introduction to the didactics of US, SGB, and ICB, a demonstration of the techniques by an expert user, as well as hands-on training of needle guidance using a gel pad and two phantoms. Three groups of participants with different levels of expertise with US-guided procedures took part in the curriculum: 12 medical students with no prior experience, 12 anesthesiologists with some experience, and five senior anesthesiologists who already applied these techniques on a regular basis. Participants evaluated the curriculum via questionnaire, and their performance of time until adequate puncture, attempts required for adequate puncture, number of corrections, and unintentional punctures was assessed. The medical students significantly increased their speed during both nerve blocks and reduced the number of attempts and corrections necessary to perform adequate ICB. The anesthesiologists with some experience also increased their speed in both blocks. The participants rated the curriculum as good to very good. The combination of theoretical teaching, expert demonstration, and hands-on training on phantoms proved useful in acquiring skills needed for US-guided procedures such as SGB and ICB, and can potentially improve graduate and post-graduate medical education.

Can Real‐Time Tissue Elastography Be Used to Assess The Healing Process of Injured Superficial Digital Flexor Tendon in Horses?

Reasons for performing studyReal‐time tissue elastography (RTE) can provide objective information associated with mechanical properties of tendon tissue and add value to the structural information obtained by greyscale ultrasound. Serial RTE assessment would be useful for monitoring and optimising safe rehabilitation for horses with tendon injury.ObjectivesTo test the hypothesis that RTE could measure change in tissue stiffness in the healing process of injured superficial digital flexor tendon (SDFT) of horses.Study designProspective field study.MethodsSix Thoroughbred horses with SDFT injury and standardised rehabilitation were used. Both greyscale and RTE images were recorded approximately every 4 weeks up to 40 weeks from occurrence. Greyscale ratio (GR: dividing the grey‐value of injured area by it of surrounding noninjured area) and strain ratio (SR: dividing the strain value of stand‐off gel pad, which can be a standard, by it of injured area) was calculated at each examination. Tissue strain is displayed by colour which suggests hard (blue), intermediate (yellow), soft (red) on RTE image. Strain of injured area was evaluated by colour‐scale grade (CSG) of 1 to 3 (1; blue to green, 2; yellow and 3; red) by 3 veterinarians who didn't know the case history.ResultsGR was returned to nearly 1 quickly within 8 weeks and it was unchanged thereafter. This continuous change of GR was best‐fitted to logarithmic trendline (r2 = 0.66). SR increased gradually up to the last examination and was best‐fitted to linear trendline (r2 = 0.89). CSG was decreased gradually and it was best‐fitted to linear trendline (r2 = 0.84). Both change of SR and CSG suggested that an injured tissue would gradually increase in stiffness.ConclusionsRTE could provide useful information regarding monitoring and optimising restoration of the tissue stiffness of tendon, even if GR was unchanged by progress of scar formation, for safer and more effective rehabilitation.Ethical animal research: All animal procedures were approved by the Ethics Committee for Laboratory Animals of the Japan Racing Association Equine Research Institute. Explicit owner informed consent for participation in this study was not stated. Sources of funding: Japan Racing Association Equine Research Institute. Competing interests: None.

Eccentric compression of large varicose veins after foam sclerotherapy using a novel silicone gel pad

ZusammenfassungZiel: Wir evaluierten eine neuartige exzentrische Kompression, die ultraschalltransparentes Silikon-Gel zwischen selbstklebenden Fo-lien als individuelles Druckpolster verwendet.Methodik: Es wurden 120 Patienten mit 148 oberflächlichen Varizen (Ø 5,1–13,7 mm; MW: 7,6) nach Schaumverödung einbezogen: A) segmental randomisiert mit fokaler Kompression durch Silikon-Gel-Polster (Venartis® SGP) für 14 Tage plus Kompressionsstrumpf KKl. 2 (KS) tagsüber für 28 Tage, oder B) nur KS. Das SGP-System besteht aus einer selbstklebenden Basisfolie, auf die Silikon dem Venenverlauf folgend aufgetragen wird. Eine zweite Folie bedeckt Gel und Basisfolie. Den Patienten war Duschen erlaubt. Ermittelt wurden Querschnittsreduktion (QR, Ultra-schallscans) sowie klinische Parameter nach 2, 4 und 8 Wochen.Ergebnisse: Segmente mit SGP zeigten gegenüber KS eine höhere QR, im Mittel 52,5 vs. 23,1 % (2 Wo), 48,4 vs. 28,9 % (4 Wo) und 66,7 vs. 39,2 % (8 Wo). Entzündungsreaktionen waren unter SGP mit 12,4 vs. 39,9 % signifikant seltener, ebenso Verfärbungen mit 10,8 vs. 35,1 %. Minithrombektomien (8,1 vs. 29,7 %) und orale Analgetika (6,8 vs. 19,6 %) wurden seltener benötigt. Unerwünschte Wirkungen: Diskrete Hautirritationen (10,1 %).Schlussfolgerung: Indikationsspezifische Silikonhärten, Dosierungen, Tragezeiten und die Höhe externer Drücke bedürfen weiterer Untersuchungen, wobei die Ultraschalltransparenz neue Wege eröffnet.

Association between the use of gel pads under patients' knees and the incidence of peroneal neuropathy following liver transplantation.

There have been intermittent reports of peroneal neuropathy (PN) occurring after liver transplantation. Although PN may not be viewed as a serious complication by liver transplant (LT) recipients who require the transplant for survival, PN can significantly reduce quality of life. The incidence of PN appears to have increased after the use of gel pads was introduced. These gel pads, which are placed under patients' knees during surgery, are used to reduce lower back strain and prevent contact between the peroneal nerve at the fibular head and the hard surface of the operating table. The aim of the present study was to investigate the association, if any, between the use of gel pads and the incidence of PN. The medical records of 261 adult LT recipients were retrospectively reviewed. The recipients were divided into gel pad (n = 167) and non-gel pad (n = 94) groups. The incidence and possible risk factors of PN were compared between the two groups. The overall incidence of PN was 8.0% (21/261). The occurrence of PN was significantly higher in the gel pad group than in the non-gel pad group (10.8% vs. 3.2%; p < 0.05). Other possible risk factors were comparable between the two patient groups. As the use of gel pads may increase the incidence of PN, we recommend against the use of gel pads under the knees of LT recipients.

SU‐E‐J‐162: Quality Assurance Procedures for MR Guided Focused Ultrasound Treatment of Bone Metastasis

Purpose:The purpose of this work is to develop and verify our quality assurance (QA) procedures to ensure the safety and efficacy of MR‐guided focused ultrasound (MRgFUS) treatment of bone metastases.Methods:A practical QA program was developed. Monthly and daily QA (DQA) procedures were performed. The major QA items included the checks of the machine hardware, software and patient safety features. Briefly, these checks/tests include: 1) the cooling system reservoir and treatment table; 2) power to the treatment table; 3) the MR coil; 4) the transducer position with MRI; 5) image display on the treatment work station; 6) the effective focal spot in 3 directions using MR thermometry; and 7) all the safety devices including a sonication lamp, and the emergency stop‐sonication switches. In order to avoid patient skin burn, it is important to remove gas bubbles in the interfaces between the treatment table and the gel pad, and the gel pad and patients skin during the patient setup. Our QA procedures have been verified and evaluated through patient treatments. Seven patients with scapula, humeral head, sacrum, ilium, pubic ramus and acetabular bone metastases were treated using MRgFUS.Results:Our study showed that all seven patients tolerated the MRgFUS treatment well. No skin toxicity or other complications were observed. The pain score (0–10) using the visual analog scale (VAS) was significantly reduced from 8.0 ± 1.1 before treatment to 4.7 ± 3.0, 3.0 ± 1.5, 3.2 ± 2.8 and 3.4 ± 1.5 at one day, one month, two months and three months after the MRgFUS treatment, respectively.Conclusion:We demonstrated that with the appropriate QA procedures, MRgFUS is a safe, effective and noninvasive treatment modality for palliation of bone metastases.

Ultrasound imaging of chitosan nerve conduits that bridge sciatic nerve defects in rats.

Ultrasound imaging of chitosan nerve conduits that bridge sciatic nerve defects in rats.

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Introduction: Therapeutic hypothermia has been the standard treatment for unconscious patients with return of spontaneous circulation(ROSC) after out-of-hospital cardiac arrest(OHCA). There are a variety of cooling methods to induce therapeutic hypothermia to cool core body temperature below 34°C. The American Heart Association (AHA) and European Resuscitation Council (ERC) guidelines recommend easy and inexpensive methods such as rapid intravenous infusion of cold saline as a priority. But, the most effective cooling technique has not been proven well. Thus we compared the cooling rate of the conventional method with cold saline bladder irrigation with the commercial hydrogel pad in OHCA patients. Methods: Data were extracted from the our hypothermia database from Jan.,2010 to Mar.,2012. The conventional method group induced hypothermia by intravenous infusion of 2000ml of 4°C cold saline with cold saline bladder irrigation. The hydrogel pad group used surface cooling gel pad (ArticSun®) after intravenous infusion of 2000ml of 4°C cold saline. The induction time was defined as time to reach up to 33°C of core body temperature from infusion of coldsaline. We compared the induction time and cooling rate between the cooling methods. Results: The 81 patients were enrolled. 57 patients were the hydrogel pad group and 24 patients were the conventional group. There were no statistical differences of baseline characteristic between 2 groups. The induction time of the conventional group (149min) was shorter than that of the hydrogel pad group (168min). The cooling rate of the conventional group (1.51°C/hr) was greater than that of the hydrogel pad group (1.48°C/hr). But, there were no statistical differences. Conclusions: The conventional method by infusion of intravenous cold saline is as effective as commercial hydrogel pad for induction of therapeutic hypothermia patients successfully resuscitated from cardiac arrest.

Effects of antiperspirant aluminum percent composition and mode of application on mock microcalcifications in mammography

ObjectiveActive ingredients in antiperspirants – namely, aluminum-based complexes – can produce radiopaque particles on mammography, mimicking microcalcifications. The present study was designed to investigate whether the appearance of antiperspirant induced radiopaque particles observed on mammograms is dependent on the percentage of aluminum-based complexes in antiperspirants and/or on their mode of application. MethodsA total of 43 antiperspirants with aluminum-based complex percentages ranging between 16% and 25% were tested. Each antiperspirant was applied to a single use plastic shield and then placed on an ultrasound gel pad, simulating breast tissue. Two experiments were performed, comparing antiperspirants based on (1) their percentage of aluminum-based complexes (20 antiperspirants) and (2) their mode of applications (solid, gel, and roll-on) (26 antiperspirants). Two experienced, blinded radiologists read images produced in consensus and assessed the appearance of radiopaque particles based on their density and shape. ResultsIn experiment 1, there was no statistically significant association between the percent aluminum composition of invisible solid antiperspirants and the density or shape of the radiopaque particles (p-values>0.05). In experiment 2, there was a statistically significant association between the shape of the radiopaque particles and the mode of application of the antiperspirant (p-value=0.0015). ConclusionsOur study suggests that the mammographic appearance of the radiopaque antiperspirant particles is not related to their percent composition of aluminum complexes. However, their mode of application appears to influence the shape of radiopaque particles, solid antiperspirants mimicking microcalcifications the most and roll-on antiperspirants the least.

Activity of Ciprofloxacin and Tobramycin-Loaded Natural Peptide Dressing on Biofilms and Planktonic Cells

Application of dressing material is generally aimed to maintain a moist environment at the wound interface, allow gaseous exchange, prevent the wound directly contact to microorganisms and remove excess exudates. The wound dressing synthesized from biocompatible materials are of interest due to the desired properties such as non-toxic, non-allergenic, non-adherent, and easily removed without trauma. The objective of this research is to synthesize a multifunctional peptide dressing which could provide an antimicrobial activity against Pseudomonas aeruginosa planktonic bacteria and biofilms and help tissue regeneration. Sample suspensions of the 6% (w/v) BSA and 8% (w/v) peptide extract heated for 30 minutes were used for hydrogel dressing preparation. For gel pad casting, 8% (w/v) BSA also heated to 100 °C for 20 minutes followed by rapid cooling in cold water. To crosslink their structure, 0.25% (w/v) NaCl solution was added. The suspensions were later cooled down at 4 °C for 2 hours. Both hydrogel dressings contained either 10 μg/ml of ciprofloxacin or 10 μg/ml of tobramycin and 10 μM of astaxanthin. The antimicrobial test indicated that the BSA hydrogel had the activity against planktonic cells with the log reduction value of 6.19 ± 0.12 for ciprofloxacin and 6.50 ± 0.51 for tobramycin. The peptide hydrogel containing ciprofloxacin and tobramycin resulted in 7.68 ± 0.33 and 6.13 ± 0.40 log reduction, respectively. Both antibiotic drugs exhibited lower effect on the viability of P. aeruginosa in colony biofilms. The qualitative results observed with the wound pads also revealed higher viability of established biofilms, suggesting the antibiotic tolerance of these biofilms. This finding aids in the development of novel biomaterial wound dressing.

Proximity Injection of Plasticizing Molecules to Self-Assembling Polymers for Large-Area, Ultrafast Nanopatterning in the Sub-10-nm Regime

While the uses of block copolymers (BCPs) with a high Flory-Huggins interaction parameter (χ) are advantageous for the improvement of resolution and line edge fluctuations of self-assembled nanoscale patterns, their slow chain diffusion results in a prolonged assembly time. Although solvent vapor annealing has shown great effectiveness in promoting the self-assembly of such BCPs, a practical methodology to achieve a uniform swelling level in wafer-scale BCP thin films has not been reported. Here, we show that a solvent-swollen polymer gel pad can be used as a highly controllable vapor source for the rapid, large-area (>200 mm in diameter) formation of sub-10-nm patterns from a high-χ BCP. The proximal injection of solvent vapors to BCP films and the systematic control of the swelling levels and temperatures can significantly boost the self-assembly kinetics, realizing the formation of well-aligned sub-10-nm half-pitch patterns within 1 min of self-assembly. Moreover, we show that the gel pad can be used for the shear-induced alignment of BCP microdomains in an extremely short time of ~5 s as well as for the generation of three-dimensional crossed-wire nanostructures with controlled alignment angles.