PEG Block Research Articles

Rational design of diblock copolymer enables efficient cytosolic protein delivery

Polymer-mediated cytosolic protein delivery demonstrates a promising strategy for the development of protein therapeutics. Here, we propose a new designed diblock copolymer which realizes efficient cytosolic protein delivery both in vitro and in vivo. The polymer contains one protein-binding block composed of phenylboronic acid (PBA) and N-(3-dimethylaminopropyl) (DMAP) pendant units for protein binding and endosomal escape, respectively, followed by the response to ATP enriched in the cytosol which triggers the protein release. The other block is PEG designed to improve particle size control and circulation in vivo. By optimizing the block composition, sequence and length of the copolymer, the optimal one (BP20) was identified with the binding block containing 20 units of both PBA and DMAP, randomly distributed along the chain. When mixed with proteins, the BP20 forms stable nanoparticles and mediates efficient cytosolic delivery of a wide range of proteins including enzymes, toxic proteins and CRISPR/Cas9 ribonucleoproteins (RNP), to various cell lines. The PEG block, especially when further modified with folic acid (FA), enables tumor-targeted delivery of Saporin in vivo, which significantly suppresses the tumor growth. Our results shall inspire the design of novel polymeric vehicles with robust capability for cytosolic protein delivery, which holds great potential for both biological research and therapeutic applications.

Quantifying Changes in Dexterity as a Result of Piano Training in People with Parkinson's Disease.

People with Parkinson's disease often show deficits in dexterity, which, in turn, can lead to limitations in performing activities of daily life. Previous studies have suggested that training in playing the piano may improve or prevent a decline in dexterity in this population. In this pilot study, we tested three participants on a six-week, custom, piano-based training protocol, and quantified dexterity before and after the intervention using a sensor-enabled version of the nine-hole peg test, the box and block test, a test of finger synergies using unidimensional force sensors, and the Quantitative Digitography test using a digital piano, as well as selected relevant items from the motor parts of the MDS-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) and the Parkinson's Disease Questionnaire (PDQ-39) quality of life questionnaire. The participants showed improved dexterity following the training program in several of the measures used. This pilot study proposes measures that can track changes in dexterity as a result of practice in people with Parkinson's disease and describes a potential protocol that needs to be tested in a larger cohort.

The effect of PEG-content and molecular weight of PEG-PPG-PEG block copolymers on the structure and performance of polyphenylsulfone ultra- and nanofiltration membranes

Thin-film composite (TFC) membranes obtained by forming a selective polyamide (PA) layer on a surface of a porous membrane-substrate via interfacial polymerization (IP) technique are the most effective membranes for nanofiltration (NF). The idea of this study is that addition of polyethylene glycol-polypropylene glycol-polyethylene glycol (PEG-PPG-PEG) block copolymers to the polyphenylsulfone (PPSU) casting solution tunes the pore structure (pore size and porosity), water contact angle and topology of the selective layer of ultrafiltration (UF) membranes. This influences the formation of PA layer via IP since membrane-substrate significantly effects the first stage of IP reaction. For the first time the effect of PEG-PPG-PEG copolymer molecular weight, content of PEG blocks and copolymer concentration in the PPSU casting solution on the structure, hydrophilicity and performance of ultrafiltration and TFC NF membranes was revealed. It was found that increase in PEG block content and PEG-PPG-PEG molecular weight led to the increase in pore size, porosity and hydrophilicity of selective layer of ultrafiltration membranes which results in the formation of thinner and more uniform PA layer with higher cross-linking degree of NF membranes via IP. It was revealed that NF membrane flux increased with the rise in the content of PEG units from 10 to 80 wt% and increase in molecular weight of PEG-PPG-PEG block copolymer. Modification of PPSU membrane-substrate yielded the increase in selectivity of the corresponding TFC NF membranes due to the formation of more uniform and denser defect-free PA layer attributed to the rise in hydrophilicity of membrane-substrate. It was found that membrane-substrate modification by PEG-PPG-PEG results in the enhancement of antifouling performance toward bovine serum albumin (flux recovery ratio is 99–100 %) and long-term stability during 48 h operation compared to the reference membrane. Modification of PPSU membrane-substrate by F38 PEG-PPG-PEG block copolymer (Mn = 5000 g mol−1, PEG block content of 80 wt%) was found to yield the TFC NF membranes with the best combination of permeation, separation and antifouling performance and long-term stability.

Recyclable and biodegradable bio-based polyurethane elastomers with exceptional mechanically properties

Bio-based polyurethanes (BPUs) have garnered significant attention due to their sustainable nature and potential to replace conventional petroleum-based PUs. This study delves into the synthesis, characterization, and application of a novel BPU variant, BPUPEG, derived from A-B-A triblock polyols. DSC tests highlighted the crystallization properties of the PEG block within BPUPEG, setting it apart from other BPU samples. Structural insights were further obtained from POM and WAXS tests, revealing the nanocrystalline structures and differences among the BPU samples. Mechanical testing showcased BPUPEGs superior fracture stress and strain, emphasizing its enhanced mechanical properties. Biodegradation experiments were conducted, underscoring the environmentally benign nature of all BPUs, with BPUPEG demonstrating a slower hydrolysis rate attributed to its PEG crystalline phase. Importantly, BPUPEGs degradation byproducts were ascertained to be non-toxic, emphasizing its eco-friendly attributes. The study also explored BPUPEGs recyclability, confirming its potential for multiple reuse cycles without degradation in mechanical properties. In conclusion, BPUPEG emerges as a sustainable, high-performance BPU, holding promise for diverse applications in the future, aligning with global sustainability and carbon reduction goals.

UCST-Type Thermoresponsive Sol-Gel Transition Triblock Copolymer Containing Zwitterionic Polymer Blocks.

Thermoresponsive sol-gel transition polymers are of significant interest because of their fascinating biomedical applications, including as drug reservoirs for drug delivery systems and scaffolds for tissue engineering. Although extensive research has been conducted on lower critical solution temperature (LCST)-type sol-gel transition polymers, there have been few reports on upper critical solution temperature (UCST)-type sol-gel transition polymers. In this study, we designed an ABA-type triblock copolymer composed of a poly(ethylene glycol) (PEG) block and zwitterionic polymer blocks that exhibit UCST-type thermoresponsive phase transitions. A sulfobetaine (SB) monomer with both ammonium and sulfonate (-SO3) groups in its side chain or a sulfabetaine (SaB) monomer with both ammonium and sulfate (-OSO3) groups in its side chain was polymerized from both ends of the PEG block via reversible addition-fragmentation chain-transfer (RAFT) polymerization to obtain PSB-PEG-PSB and PSaB-PEG-PSaB triblock copolymers, respectively. Although an aqueous solution containing the PSB-PEG-PSB triblock copolymer showed an increase in viscosity upon cooling, it did not undergo a sol-to-gel transition. In contrast, a sol-to-gel transition was observed when a phosphate-buffered saline containing PSaB-PEG-PSaB was cooled from 80 °C to 25 °C. The PSaB blocks with -OSO3 groups exhibited a stronger dipole-dipole interaction than conventional SB with -SO3 groups, leading to intermolecular association and the formation of a gel network composed of PSaB assemblies bridged with PEG. The fascinating UCST-type thermoresponsive sol-gel transition properties of the PSaB-PEG-PSaB triblock copolymer suggest that it can provide a useful platform for designing smart biomaterials, such as drug delivery reservoirs and cell culture scaffolds.

Host-Guest Interaction Mediated Interfacial Co-Assembly of Cyclodextrin and Bottlebrush Surfactants for Precisely Tunable Photonic Supraballs.

Investigations of host-guest interactions at water-oil (w/o) interfaces are limited in single emulsion systems producing simple self-assembled objects with limited uses. Here, within hierarchically ordered water-in-oil-in-water (w/o/w) multiple emulsion droplets, interfacial self-assembly of (polynorbornene-graft-polystyrene)-block-(polynorbornene-graft-polyethylene glycol) (PNPS-b-PNPEG) bottlebrush block copolymers can be precisely controlled through host-guest interactions. α-Cyclodextrin (α-CD) in the aqueous phase can thread onto PEG side chains of the bottlebrush surfactants adsorbed at the w/o interface, leading to dehydration and collapsed chain conformation of the PEG block. Consequently, spherical curvature of the w/o internal droplets increases with the increased asymmetry of the bottlebrush molecules, producing photonic supraballs with precisely tailored structural parameters as well as photonic bandgaps. This work provides a simple but highly effective strategy for precise manipulation of complex emulsion systems applicable in a variety of applications, such as photonic pigments, cosmetic products, pesticides, artificial cells, etc.

Features of Interaction of Lysozyme with PGLU–PEG Block Copolymers

Features of Interaction of Lysozyme with PGLU–PEG Block Copolymers

Combined Effects of Brunnstorm Movement Therapy and Low-Level Laser Therapy on Upper Limb Function and Hand Dexterity in Chronic Stroke Patient

Background: Stroke remains a leading cause of disability worldwide, necessitating innovative rehabilitation strategies to enhance recovery and improve quality of life. The integration of Brunnstrom movement therapy and low-level laser therapy (LLLT) presents a novel approach to addressing the complexities of stroke rehabilitation, focusing on improving upper limb function and hand dexterity. Objective: This study aimed to evaluate the combined effects of Brunnstrom movement therapy and LLLT on upper limb function and hand dexterity in chronic stroke patients, providing insights into potentially enhancing rehabilitation outcomes. Methods: A randomized controlled trial was conducted involving 48 chronic stroke patients, divided equally into two groups to receive either Brunnstrom movement therapy or LLLT. The study spanned six months, with assessments including the Modified Ashworth Scale (MAS), Nine-Hole Peg Test, Box and Block Test, Fugl-Meyer Assessment, and Handheld Dynamometer. Data were analyzed using SPSS version 25, employing descriptive statistics, chi-square tests, and Mann-Whitney U tests to compare outcomes between groups. Results: Significant improvements were noted in both groups, with the LLLT group showing superior performance in the Nine-Hole Peg Test (p<0.001), Box and Block Test (p<0.001), and Fugl-Meyer Assessment (p<0.001) compared to baseline. The MAS scores indicated a significant reduction in muscle spasticity over time in both groups, with the LLLT group exhibiting a more substantial decrease (p=0.003 at week 6). Conclusion: The study demonstrated that combining Brunnstrom movement therapy with LLLT could significantly enhance upper limb function and hand dexterity in chronic stroke patients. These findings advocate for the integration of innovative and non-invasive therapies into rehabilitation programs, potentially setting a new benchmark in stroke recovery practices.

Influence of cognition on the correlation between objective and subjective upper limb measures in people with multiple sclerosis.

A comprehensive assessment of upper limb (UL) function is mandatory in people with multiple sclerosis (PwMS), and the use of multiple objective and subjective measures is advisable. Findings on the role of cognitive impairment on the assessment of UL function are scant and inconclusive. The present study investigated the influence of cognitive function on the distribution of objective and subjective UL measures and on their association. In the cross-sectional study, subjects with a diagnosis of MS, age ≥ 18years, right-hand dominance, no presence of orthopedic UL impairment, or other neurological diseases were recruited. The assessment protocol included the Nine-Hole Peg Test (9-HPT), Box and Block Test (BBT), and hand grip strength (HGS), a validated PROM (MAM-36), and the Symbol Digit Modalities Test (SDMT). Two hundred forty-six PwMS were recruited (158 females, mean age = 51.65 ± 13.45years; mean EDSS = 5.10 ± 1.88) Subject with mild-to-moderate cognitive impairment (SDMT ≤ - 2 SD of normative values) scored lower on the 9-HPT and higher on the BBT and MAM-36 when compared with subject with no cognitive impairment. Cognitive impairment showed a small but significant effect on the association between 9-HPT scores and the MAM-36. Findings suggest that cognitive impairment is associated with subjects' performance on 9-HPT, BBT, and MAM-36 (but not HGS), resulting in scores indicating a poorer UL function. Interestingly, cognitive impairment slightly affected the congruence between subjective and objective UL measures, although only minor differences in the correlation pattern across groups reporting different cognitive performances emerged.

The effect of comb length on the in vitro and in vivo properties of self-assembled poly(oligoethylene glycol methacrylate)-based block copolymer nanoparticles.

Comb copolymer analogues of poly(lactic acid)-polyethylene glycol block copolymers (PLA-b-PEG) offer potential to overcome the inherent chemistry and stability limitations of their linear block copolymer counterparts. Herein, we examine the differences between P(L)LA10K-b-PEG10K and linear-comb copolymer analogues thereof in which the linear PEG block is replaced by poly(oligo(ethylene glycol) methacrylate) (POEGMA) blocks with different side chain (comb) lengths but the same overall molecular weight. P(L)LA10K-b-POEGMA47510K and P(L)LA10K-b-POEGMA200010K block copolymers were synthesized via activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP) and fabricated into self-assembled nanoparticles using flash nanoprecipitation via confined impinging jet mixing. Linear-comb copolymer analogues based on PLA-b-POEGMA yielded smaller but still well-controlled nanoparticle sizes (88 ± 2 nm and 114 ± 1 nm respectively compared to 159 ± 2 nm for P(L)LA10K-b-PEG10K nanoparticles) that exhibited improved colloidal stability relative to linear copolymer-based nanoparticles over a 15 day incubation period while maintaining comparably high cytocompatibility, although the comb copolymer analogues had somewhat lower loading capacity for doxorubicin hydrochloride. Cell spheroid studies showed that the linear-comb copolymers promoted enhanced tumor transport and thus cell killing compared to conventional linear block copolymers. In vivo studies showed all NP types could passively accumulate within implanted CT26 tumors but with different accumulation profiles, with P(L)LA10K-b-POEGMA200010K NPs showing continuous accumulation throughout the full 24 h monitoring period whereas tumor accumulation of P(L)LA10K-b-POEGMA47510K NPs was significant only between 8 h and 24 h. Overall, the linear-comb copolymer analogues exhibited superior stability, biodistribution, spheroid penetration, and inherent tunability over linear NP counterparts.

Influence of miscibility of PEG-B-PPG-B-PEG/EPOXY systems on thermal, mechanical and fracture properties

Epoxy matrix blends with poly (ethylene glycol)-block-poly (propylene glycol)-block-poly (ethylene glycol) triblock copolymer (PEG-b-PPG-b-PEG) with 30% PEG blocks were elaborated and investigated. The systems were prepared by the casting method with cure at 100 °C, with different amounts of copolymer in the epoxy matrix, and with the aim of evaluating the influence of the modifier on the properties of the blends. By DSC it was verified that the glass transition temperature relating to the matrix phase decreased in systems with copolymer in relation to neat epoxy, thus the blends formed partially miscible systems. On the other hand, phases separation or microdomains of the block copolymer within the epoxy matrix were not discernible by scanning electron microscopy. In general, the addition of the block copolymer impaired the mechanical properties evaluated in the tensile test. However, the fracture mechanisms observed on the fracture surface of the blends indicate that an improvement in the toughness of the systems may have occurred due to the crack pinning and crack deflection mechanisms.

PPG-PEG-PPG/Epoxy systems cured at 100 °C: relationship between miscibility, microstructure, thermal and mechanical properties

This article evaluated the thermal, mechanical, morphological and fracture properties of systems with poly (ethylene glycol)–poly(propylene glycol)–poly(ethylene glycol) (PPG-PEG-PPG) triblock copolymer, with molecular weight 2000 g•mol−1 and 50% PEG in its composition, in DGEBA/DDM epoxy matrix. Systems with 10, 20 and 30 wt.% copolymer were prepared by in-situ polymerization and curing at 100 °C. In the differential scanning calorimetry (DSC) analysis, the characteristic temperatures of both the copolymer and the matrix in the binary systems were verified, indicating that phase separation had occurred. However, the glass transition temperature referring to the epoxy phase (Tg-E) occurred at lower temperatures than in neat matrix, which indicates partial miscibility in binary systems. The epoxy/copolymer systems presented a Young's modulus higher than the neat matrix, and without loss of mechanical resistance, reinforcing the miscibility of the PEG block in the blends and a microstructure with nanophase separation. When evaluating the fracture surface of the blends by scanning electron microscopy, the presence of deflection and crack immobilization mechanisms was observed, but no phase separation of the copolymer was observed. In this way, the systems studied showed partial miscibility with the formation of nanophases at the curing temperature of 100 °C, influencing Tg-E and improving the stiffness of the matrix.

Widening the Application Range of PLA‐Based Thermoplastic Materials through the Synthesis of PLA‐Polyether Block Copolymers: Thermal, Tensile, and Rheological Properties

AbstractPolyethylene glycol (PEG), polypropylene glycol (PPG), and poly(ethylene glycol‐co‐propylene glycol) (PEPG) of number average molar masses (Mn) of 6–20 kDa are used as macroinitiators in the ring‐opening polymerization (ROP) of l‐lactide to synthesize high molar mass (50 kDa < MnCopo < 120 kDa) PLLA‐b‐polyether‐b‐PLLA linear triblock and starblock copolymers. At the studied block lengths, PEG and PEPG blocks exhibit miscibility with the PLLA blocks in the amorphous domains leading to a plasticization effect. As the PEG or PEPG block content is increased to 18 %wt, the Tg (Tg ≈ 24 °C) and the elastic modulus (E ≈ 500 MPa) are reduced, while the elongation at break (εb ≈ 280%) and crystallization rate are increased. At the same time, small angle oscillatory shear (SAOS) rheometric measurements show that the plasticized copolymers have a reduced melt viscosity. In contrast, SAOS and DSC measurements of the PPG‐containing block copolymers reveal phase separation of the PPG and PLA blocks leading to microstructures in the melt. Tensile tests show that the phase‐separated PPG‐containing block copolymers are more ductile than PLA homopolymers, but more brittle than the PEG‐ or PEPG‐plasticized block copolymers.

PH-Responsive polymer boosts cytosolic siRNA release for retinal neovascularization therapy

Small interfering RNA (siRNA) has a promising future in the treatment of ocular diseases due to its high efficiency, specificity, and low toxicity in inhibiting the expression of target genes and proteins. However, due to the unique anatomical structure of the eye and various barriers, delivering nucleic acids to the retina remains a significant challenge. In this study, we rationally design PACD, an A-B-C type non-viral vector copolymer composed of a hydrophilic PEG block (A), a siRNA binding block (B) and a pH-responsive block (C). PACDs can self-assemble into nanosized polymeric micelles that compact siRNAs into polyplexes through simple mixing. By evaluating its pH-responsive activity, gene silencing efficiency in retinal cells, intraocular distribution, and anti-angiogenesis therapy in a mouse model of hypoxia-induced angiogenesis, we demonstrate the efficiency and safety of PACD in delivering siRNA in the retina. We are surprised to discover that, the PACD/siRNA polyplexes exhibit remarkable intracellular endosomal escape efficiency, excellent gene silencing, and inhibit retinal angiogenesis. Our study provides design guidance for developing efficient nonviral ocular nucleic acid delivery systems.

Permeability of Skin-Mimicking Cell Coatings by Polymers of Complex Architecture Based on Polyoxazolines

In the scope of drug delivery, the transdermal route is desirable because it provides attainable therapeutic concentrations and has minimal systemic side effects. To make the skin a feasible route for the delivery of therapeutic agents, the biggest challenge is overcoming its natural coating. In this paper, we investigate the effect of the architectures (homopolymer vs. block copolymer vs. hybrid block–graft copolymer) of several amphiphilic polymeric derivatives of poly(2-oxazoline) on skin permeability. The block copolymers are composed of a hydrophobic poly(2-oxazoline) block and a hydrophilic PEG block. The hybrid block–graft copolymers are obtained by grafting hydrophobic side chains of polycaprolactone to a poly(2-oxazoline) backbone. We used the commercially available EpiDerm™ by MatTek, composed of human epidermal cells, as a model of human skin. Two parameters of skin permeation are reported: penetration rate and lag time. We hypothesize that the skin permeation characteristics correlate with the critical micelle concentration and particle size of the studied polymers, while both parameters are a function of the complex architectures of the presented macromolecular constructs. While homopolymer poly(2-oxazolines) show the least permeation, the block copolymers demonstrate partial permeation. The hybrid block–graft copolymers exhibited full penetration through the model skin samples.

Water-soluble PEG segmented mannose-based macromolecules: Synthesis, characterization and their biocompatibility

The macromolecular architectures, namely mannose-based methacrylate acetyl-mannopyranoside and PEG block copolymers [AB type copolymer [PEG-b-PMAM], poly(ethyleneglycol)-b-poly(methacryl-2,3,4,6-tetra-O-acetyl-D-mannopyranoside) and ABA type copolymer [PMAM-b-PEG-b-PMAM], poly(methacryl-2,3,4,6-tetra-O-acetyl-D-mannopyranoside)-b-poly(ethyleneglycol)-b-poly(methacryl-2,3,4,6-tetra-O-acetyl-D-mannopyranoside)] were synthesized by atom transfer radical polymerization (ATRP) method that were deacetylated to generate the corresponding water-soluble and biocompatible glycopolymer macromolecules. The molecular weight of acetyl and deacetylate macromolecules was in the range of 7083–9499 and 4659–6026, as determined by GPC and proton NMR spectra. The 5 % decomposition temperatures for acetylated methacrylate macromolecules (218–299 °C) were higher than the corresponding water-soluble macromolecules (204–248 °C). The conjugation of poly(methacryl-2,3,4,6-tetra-O-acetyl-D-mannopyranoside) (PMAM) segment with the PEG block decreased the glass transition (Tg) value, and the water-soluble macromolecules displayed Tg in the range of 92–95 °C. The biocompatibility of the synthesized water-soluble mannose-based macromolecules was determined using Human Bone Derived Cells (HBDC) culture with the TCP (Tissue culture plastic) template as control. Using three different concentrations of the synthesized glycopolymers, HBDC's were cultured for 1, 3, and 7 days. The effect of mannomethacrylate macromolecules on mitochondrial activity of HBDC's was estimated using colorimetry that showed the conversion of MTS [3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl-tetrazolium-bromide] to formazan (MTS assay). ABA type diblock copolymer architecture exhibited increased absorbance values of 3 and 7 day cultures at 1–100 M concentrations, with the highest values observed at a concentration of 1 M for day 3 cultures. The design of these novel mannose-based macromolecules is important for improving cell proliferation, cell adhesion, and osteointegration efficiency.

PH-Responsive Poly(ethylene glycol)-b-poly(2-vinylpyridine) Micelles for the Triggered Release of Therapeutics

The use of pH-responsive polymeric micelles is a promising approach to afford the targeted, pH-mediated delivery of hydrophobic drugs within the low-pH tumour milieu and intracellular organelles of cancer cells. However, even for a common pH-responsive polymeric micelle system-e.g., those utilising poly(ethylene glycol)-b-poly(2-vinylpyridine) (PEG-b-PVP) diblock copolymers-there is a lack of available data describing the compatibility of hydrophobic drugs, as well as the relationships between copolymer microstructure and drug compatibility. Furthermore, synthesis of the constituent pH-responsive copolymers generally requires complex temperature control or degassing procedures that limit their accessibility. Herein we report the facile synthesis of a series of diblock copolymers via visible-light-mediated photocontrolled reversible addition-fragmentation chain-transfer polymerisation, with a constant PEG block length (90 repeat units (RUs)) and varying PVP block lengths (46-235 RUs). All copolymers exhibited narrow dispersity values (Đ ≤ 1.23) and formed polymeric micelles with low polydispersity index (PDI) values (typically <0.20) at physiological pH (7.4), within a suitable size range for passive tumour targeting (<130 nm). The encapsulation and release of three hydrophobic drugs (cyclin-dependent kinase inhibitor (CDKI)-73, gossypol, and doxorubicin) were investigated in vitro at pH 7.4-4.5 to simulate drug release within the tumour milieu and cancer cell endosome. Marked differences in drug encapsulation and release were observed when the PVP block length was increased from 86 to 235 RUs. With a PVP block length of 235 RUs, the micelles exhibited differing encapsulation and release properties for each drug. Minimal release was observed for doxorubicin (10%, pH 4.5) and CDKI-73 exhibited moderate release (77%, pH 4.5), whereas gossypol exhibited the best combination of encapsulation efficiency (83%) and release (91% pH 4.5) overall. These data demonstrate the drug selectivity of the PVP core, where both the block molecular weight and hydrophobicity of the core (and accordingly the hydrophobicity of the drug) have a significant effect on drug encapsulation and release. These systems remain a promising means of achieving targeted, pH-responsive drug delivery-albeit for select, compatible hydrophobic drugs-which warrants their further investigation to develop and evaluate clinically relevant micelle systems.

The Benefits of Combining Mixed Virtual Reality Exergaming with Occupational Therapy for Upper Extremity Dexterity

Virtual Reality (VR) is expanding worldwide in education, training, gaming, and healthcare to achieve distinct outcomes. This paper aimed to identify to what extent physiotherapy based on mixed VR technology and occupational therapy serves the functionality of healthy subjects’ upper extremities; it also analyzed the benefits of this protocol for therapy guidelines in hand dexterity re-habilitation. Fifteen VR exergames and occupational therapy sessions were performed for 60 min in three weeks with a sample of sixteen people. The Jebsen Taylor Hand Function Test Scale (JTHFTS), Nine-Hole Peg test (9 Hole), Box and Blocks Test (BBT), and Timed Functional Test for the Arm and Shoulder (TFAST) were used for pre and post-therapy assessment. Linear regression was used to identify healthy subjects’ main tasks, predicting upper extremity dexterity. The results of pre- and post-exercise assessments suggested significant improvements for both upper extremities, dominant and non-dominant. BBT, the nine-hole peg test, and FAST showed significant differences in pre- and post-therapy, favoring prophylactical exercises. Hence, in the linear regression results for the dominant hand, five models emerged as potential predictors for upper extremity agility. The capacity to pick up large light objects seemed to bring the most critical influence on hand dexterity. However, regarding the non-dominant hand, the results suggested that writing ability was the most potent predictor of dexterity. In this respect, the protocol used in this research can be used as a guideline for further upper extremity dexterity training since VR exergames combined with occupational therapy can bring essential contributions to upper limb proprioception and dexterity functioning.

Reversible Dehydration-Hydration of Poly(ethylene glycol) in Langmuir Monolayers of a Diblock Copolymer Inferred from Changes in Filament Curvature.

We investigated changes in the hydration state of poly(ethylene glycol) (PEG) through morphological changes in Langmuir monolayers of a PEG-poly(l-lactide) (PlLA) (PEG-b-PlLA) diblock copolymer. When the PEG blocks were hydrated, we observed a remarkable morphology of bundles of ring-like filaments, arranged concentrically, yielding densely packed disk-like objects with a hollow center. We attribute the uniform curvature of these filaments to a strong mismatch between the molecular volumes occupied by PlLA blocks and hydrated PEG blocks. Under the constraint that each hydrated PEG block is attached to a hydrophobic PlLA block anchored to the air-water interface, this mismatch of molecular volumes caused strong repulsion within the PEG layer, in particular when the PlLA blocks packed tightly. Induced by a transition in the ordering of the PlLA blocks, the PEG blocks lost their hydration shell and packed into a dense polymer brush, accompanied by a reduction of the pressure within the PEG layer. During this packing process, the curvature of the filaments was eliminated and the ring-like filaments fractured into small linear pieces. Upon compression, the linear pieces coalesced and formed long filaments aligned in parallel. Importantly, upon expansion of the Langmuir film, these changes in morphology were reversible, and the PEG blocks could be rehydrated and bundles of concentrically arranged ring-like filaments were reformed. We conclude that the change in curvature of the filaments provides a means for distinguishing between the hydrated and dehydrated states of PEG.

Fine pore tailoring of PSf-b-PEG membrane in sub-5 nm via phase-inversion

It is highly important but challenging to fabricate polymeric separation membranes with pore size in sub-5 nm via the non-solvent induced phase separation (NIPS) process. Herein, we reported a simple but effective method to precisely tailor the pore size of polysulfone-block-polyethylene glycol (PSf-b-PEG) membrane in sub-5 nm via NIPS. Selective solvents of tetramethylene sulfone (Ts) and tetrahydrofuran (THF) towards the corresponding PEG block and PSf block in PSf-b-PEG were mixed at various ratios to tailor the casting solution properties and to finely tailor the pore size of the PSf-b-PEG membranes. The membrane formation mechanism was also investigated to reveal that the PSf-b-PEG membrane exhibited intertwined and fused nanofibrous structure with relatively high porosity and extremely strong mechanical strength. As the content of evaporative THF in the casting solution increased from 42.5 wt% to 85.0 wt%, the MWCO of the PSf-b-PEG membranes decreased from 127 kDa to 6.6 kDa, and the mean effective pore size of the membranes shrank from 15 nm to 2 nm, greatly exceeding the tailorable range and the minimum threshold of the pore size of PSf and PES membranes. Impressively, even if the pore size of the membrane was 2 nm, the pure water permeance of the membrane was still as high as 7 L m−2 h−1 bar−1, indicating the great potential of the PSf-b-PEG membranes for practical applications.