Dutasteride in the treatment of frontal fibrosing alopecia: Systematic review and meta-analysis.

Frontal fibrosing alopecia (FFA) is a scarring alopecia with fronto-temporo-parietal hairline recession. Although no proven treatment for FFA exists, dutasteride has been suggested as a potential treatment option. We aimed to evaluate the therapeutic response of oral dutasteride in FFA patients. The identification and selection of studies were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis 2020 criteria. To assess the risk of bias for each study, we used the Cochrane's risk of bias in non-randomized studies of interventions (ROBINS-I) assessment tool. A random effects model meta-analysis was performed. Estimated proportion of stabilization for eligible studies was calculated to evaluate the effectiveness of dutasteride for treating FFA. Among patients who achieved stabilization, subgroup analysis was conducted on those showing improvement. Seven studies including 366 patients who received oral dutasteride were identified. The estimated proportion of patients who experienced stabilization of FFA with oral dutasteride was 0.628 (95% CI: 0.398-0.859). In subgroup analyses of patients who experienced improvement, the estimated proportion of improvement was 0.356 (95% CI: 0.163-0.549). In this systematic review and meta-analysis, oral dutasteride revealed to be a good treatment option for disease stabilization or improvement in patients with FFA.

Catechol-Amyloid Interactions.

This review introduces multifaceted mutual interactions between molecules containing a catechol moiety and aggregation-prone proteins. The complex relationships between these two molecular species have previously been elucidated primarily in a unidirectional manner, as demonstrated in cases involving the development of catechol-based inhibitors for amyloid aggregation and the elucidation of the role of functional amyloid fibers in melanin biosynthesis. This review aims to consolidate scattered clues pertaining to catechol-based amyloid inhibitors, functional amyloid scaffold of melanin biosynthesis, and chemically designed peptide fibers for providing chemical insights into the role of the local three-dimensional orientation of functional groups in manifesting such interactions. These orientations may play crucial, yet undiscovered, roles in various supramolecular structures.

Enhanced Oral Bioavailability of Rivaroxaban-Loaded Microspheres by Optimizing the Polymer and Surfactant Based on Molecular Interaction Mechanisms.

This study aimed to develop microspheres using water-soluble carriers and surfactants to improve the solubility, dissolution, and oral bioavailability of rivaroxaban (RXB). RXB-loaded microspheres with optimal carrier (poly(vinylpyrrolidone) K30, PVP) and surfactant (sodium lauryl sulfate (SLS)) ratios were prepared. 1H NMR and Fourier transform infrared (FTIR) analyses showed that drug-excipient and excipient-excipient interactions affected RXB solubility, dissolution, and oral absorption. Therefore, molecular interactions between RXB, PVP, and SLS played an important role in improving RXB solubility, dissolution, and oral bioavailability. Formulations IV and VIII, containing optimized RXB/PVP/SLS ratios (1:0.25:2 and 1:1:2, w/w/w), had significantly improved solubility by approximately 160- and 86-fold, respectively, compared to RXB powder, with the final dissolution rates improved by approximately 4.5- and 3.4-fold, respectively, compared to those of RXB powder at 120 min. Moreover, the oral bioavailability of RXB was improved by 2.4- and 1.7-fold, respectively, compared to that of RXB powder. Formulation IV showed the highest improvement in oral bioavailability compared to RXB powder (AUC, 2400.8 ± 237.1 vs 1002.0 ± 82.3 h·ng/mL). Finally, the microspheres developed in this study successfully improved the solubility, dissolution rate, and bioavailability of RXB, suggesting that formulation optimization with the optimal drug-to-excipient ratio can lead to successful formulation development.

Revisional triangular fibrocartilage complex (TFCC) repair using arthroscopic one-tunnel transosseous suture: preliminary results.

PURPOSE: The purpose of this study was to report the clinical outcome of revision arthroscopic triangular fibrocartilage complex (TFCC) foveal repair using a one-tunnel transosseous suture technique after failed primary TFCC repair. METHODS: Consecutive patients treated with arthroscopic TFCC foveal repair using the uniform one-tunnel transosseous suture technique after failed TFCC repair from 2014 to 2018 were retrospectively reviewed. The clinical outcome was evaluated using the Modified Mayo Wrist Score (MMWS) and the Quick Disabilities of the Arm, Shoulder, and Hand (Quick-DASH) score. The Visual Analog Scale (VAS) for pain, stability of the distal radioulnar joint (DRUJ), grip strength, and active range of motion (ROM) of the wrist joint also were assessed. RESULTS: This study cohort consisted of eight patients, and their mean time to revision after initial surgery was 15.1 months. Previous surgeries were performed using an arthroscopy-assisted mini-open TFCC repair in six cases, an arthroscopic all-inside repair in one case, and an arthroscopic transosseous suture technique in the remaining case. After revisional TFCC foveal repair, all patients demonstrated improved pain and a stable DRUJ. Participants showed improvement in grip strength and mean active wrist ROM. There was improvement in MMWS (from 58.6 to 87.5) and Quick-DASH score (from 46.9 to 12.2) during the mean follow-up of 15.6 months (range: 8-36 months). CONCLUSION: Based on the results of this study, remaining ulnar TFCC remnants may be appropriate for sufficient stable repair using an arthroscopic one-tunnel transosseous suture technique after failed primary repair. However, only a small number of patients was examined. A larger number has to be investigated to confirm the promising preliminary results. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Evaluation of thermal properties and acetaldehyde adsorption performance of sustainable composites using waste wood and biochar.

In order to vitalize the use of wood, which is a sustainable resource, increase the utilization of resources through the recycling of wood waste, and reduce environmental pollution in the waste disposal process, biocomposite was manufactured by using biochar which can be produced with wood waste and is effective in carbon isolation. The thermal characteristics and acetaldehyde adsorption performance of the prepared biocomposite were evaluated based on the pore characteristics, surface functional groups, crystal structure, and elemental analysis results of the biochar. As a result of the experiment, as the content of biochar increased, the thermal conductivity of the biocomposite decreased and the specific heat was not affected. The acetaldehyde concentration tended to decrease as the content of biochar increased, adsorbed up to 4.4685 ppm of acetaldehyde more than the reference. From these results, it is judged that the biocomposite produced in this study can function as a sustainable composite that uses waste wood to improve indoor air quality and satisfies the performance as a building material.

Evaluation of hygrothermal performance of wood-derived biocomposite with biochar in response to climate change.

Wood is a sustainable resource and building material. It provides an excellent response to climate change and has excellent insulation performance. However, structural defects may occur due to decay from moisture, resulting in poor dimensional stability. The rich organic substances contained in wood can lead to mold when the moisture content is consistently high, adversely affecting the health of occupants. Therefore, we attempted to compensate for the disadvantages of wood in regard to water stability while maintaining the high thermal insulation performance and carbon dioxide storage capacity, using biochar from thermally decomposed spruce under oxygen limiting conditions. A wood-derived biocomposite was prepared by mixing biochar and soft wood-based chips using the hot-press method, and the thermal conductivity, specific heat, water vapor resistance factor, moisture adsorption, and moisture desorption performances were analyzed. The thermal conductivity of WB10 with 10 wt% biochar content was 0.09301 W/mK. This is a 7.98% decrease from 0.10108 W/mK, the thermal conductivity of WB0 without biochar. The water vapor resistance factor tended to increase when the biochar ratio increased. As the proportion of biochar increased, the equilibrium moisture content in high relative humidity tended to decrease, and it was found that the moisture adsorption and desorption performances were affected by the ratio of the biochar. Therefore, wood-derived biocomposites using biochar can be used in environmentally friendly materials, with improved thermal insulation performance and water stability.

Development of evidence-based consensus on critical issues in the management of patients with vitiligo: A modified Delphi study.

BACKGROUND/PURPOSE: Vitiligo remains a major challenge in dermatology. However, much of the treatment remains unclear, because little evidence is available. We sought to answer some critical questions pertaining to management of vitiligo patients. METHODS: A modified Delphi process among 31 vitiligo experts was conducted. A total of 12 clinical vitiligo treatment questions without clear answers were collected via a vote. To address each question, two members performed systematic literature reviews and prepared draft statements along with the levels of evidence and strength of recommendation. After reviewing the draft, all expressed their extent of agreement from 1 (strong disagreement) to 9 (strong agreement) for each item. The drafts were revised to reflect suggested comments. Discussion continued until all members agreed with the ultimate decision. RESULTS: The consensus process was completed after five rounds. We identified the best answers to 12 key questions, including issues on long-term phototherapy, systemic and topical corticosteroids, topical calcineurin inhibitors, immunosuppressants, excimer laser treatment, and surgical interventions. CONCLUSION: This consensus would complement current guidelines and aid both physician and patient decision-making in the treatment of vitiligo.

Influence of TFCC foveal tear on the location of lunate chondromalacia in ulnar impaction syndrome.

OBJECTIVE: The purpose of this study was to identify the location of lunate chondromalacia and to compare the difference in location according to presence or absence of triangular fibrocartilage complex (TFCC) foveal tear, which induces distal radioulnar joint (DRUJ) instability. METHODS: We performed a retrospective study of 97 patients (102 wrists) who were diagnosed with and treated for idiopathic ulnar impaction syndrome (UIS) between 2014 and 2018. Subjects were divided into two groups according to presence or absence of TFCC foveal tear with DRUJ instability. Group I had UIS without a TFCC foveal tear (52 wrists, mean age of 43.2 years), while Group II had UIS with a TFCC foveal tear (50 wrists, mean age of 45.3 years). There was no significant difference in age, sex, or duration of symptoms between the two groups. All patients underwent wrist MR Arthrography (MRA) in the same gantry, and all scanned coronal sections of the lunate were standardized into 10 slices, including the whole anteroposterior width of the lunate. Each slice was sequentially numbered from dorsal to volar side, and the location of chondromalacia was marked in each numbered section. Radiological parameters including ulnar variance and ulnolunate distance (ULD), which indicated the distance between the ulnar head and lunate, were measured in the wrist series. RESULTS: The most frequent location of lunate chondromalacia was slightly to the volar side of the lunate in both groups. Group I showed a higher frequency of chondromalacia in the volar side of the lunate. In Group II, chondromalacia was identified with high frequency not only on the volar side of the lunate but also on the dorsal side. In other words, Group II showed broader chondromalacia in the lunate. There was no significant difference in ulnar variance (Group I, 3.19 ± 1.42 mm; Group II, 2.76 mm ± 1.67 mm) or ulnolunate distance (Group I, 1.66 ± 0.94 mm; Group II, 2.05 mm ± 0.87 mm). The average ULD decreased during radial deviation but increased during ulnar deviation. CONCLUSION: This study showed that lunate chondromalacia associated with idiopathic ulnar impaction syndrome occurs more frequently on the volar side of the lunate. Also, TFCC foveal tear, which causes DRUJ instability, leads to broader lunate chondromalacia in idiopathic ulnar impaction syndrome. Therefore, further analysis of the pattern of lunate chondromalacia can provide a clue for DRUJ instability.

Protective Effects of Ethanolic Extract from Rhizome of Polygoni avicularis against Renal Fibrosis and Inflammation in a Diabetic Nephropathy Model.

Progressive diabetic nephropathy (DN) in diabetes leads to major morbidity and mortality. The major pathological alterations of DN include mesangial expansion, extracellular matrix alterations, tubulointerstitial fibrosis, and glomerular sclerosis. Polygoni avicularis is widely used in traditional oriental medicine and has long been used as a diuretic, astringent, insecticide and antihypertensive. However, to the best of the authors' knowledge, the effects of the ethanolic extract from rhizome of Polygoni avicularis (ER-PA) on DN have not yet been assessed. The present study aimed to identify the effect of ER-PA on renal dysfunction, which has been implicated in DN in human renal mesangial cells and db/db mice and investigate its mechanism of action. The in vivo experiment was performed using Polygoni avicularis-ethanol soluble fraction (ER-PA) and was administrated to db/db mice at 10 and 50 mg/kg dose. For the in vitro experiments, the human renal mesangial cells were induced by high glucose (HG, 25 mM). The ER-PA group showed significant amelioration in oral glucose tolerance, and insulin resistance index. ER-PA significantly improved the albumin excretion and markedly reduced plasma creatinine, kidney injury molecule-1 and C-reactive protein. In addition, ER-PA significantly suppressed inflammatory cytokines. Histopathologically, ER-PA attenuated glomerular expansion and tubular fibrosis in db/db mice. Furthermore, ER-PA suppressed the expression of renal fibrosis biomarkers (TGF and Collagen IV). ER-PA also reduced the NLR family pyrin domain containing 3 inflammatory factor level. These results suggest that ER-PA has a protective effect against renal dysfunction through improved insulin resistance as well as the inhibition of nephritis and fibrosis in DN.

Effect of eco-friendly pervious concrete with amorphous metallic fiber on evaporative cooling performance.

Impervious pavements exist in large proportions in most cities owing to the high-impact development of the transportation infrastructure. However, this type of pavement causes environmental issues such as waterlogging, floods, and urban heat islands. Pervious concrete (PC), which is a novel pavement material characterized by a porous structure that allows water to percolate through it, is an important solution to these issues. This study investigates the evaporative cooling performance of eco-friendly PC with blast-furnace slag (BFS) as a cement replacement and amorphous metallic fiber (AMF) that helps to accelerate the evaporative cooling. The thermophysical properties, water permeability, and water absorption capability of the manufactured PC were measured. In addition, a scale model test and thermal conductivity analysis of the manufactured PC were conducted to evaluate the evaporative cooling effect. The results indicate that the physical and mechanical properties of the manufactured PC are typically similar to those of other PCs, and its water absorption rate reaches 1 mm/s. Relatively low water permeability helps the PCs to absorb more water, contributing to accumulate a large amount of water in the material for evaporative cooling. In addition, AMF contributes to increase thermal conductivity of PC, which allow the water inside the PCs to evaporate faster. The result shows that a higher thermal conductivity of the manufactured PC increases the evaporative cooling effect.

Enzymatically degradable, starch-based layer-by-layer films: application to cytocompatible single-cell nanoencapsulation.

The build-up and degradation of cytocompatible nanofilms in a controlled fashion have great potential in biomedical and nanomedicinal fields, including single-cell nanoencapsulation (SCNE). Herein, we report the fabrication of biodegradable films of cationic starch (c-ST) and anionic alginate (ALG) by electrostatically driven layer-by-layer (LbL) assembly technology and its application to the SCNE. The [c-ST/ALG] multilayer nanofilms, assembled either on individual Saccharomyces cerevisiae or on the 2D flat gold surface, degrade on demand, in a cytocompatible fashion, via treatment with α-amylase. Their degradation profiles are investigated, while systematically changing the α-amylase concentration, by several surface characterization techniques, including quartz crystal microbalance with dissipation monitoring (QCM-D) and ellipsometry. DNA incorporation in the LbL nanofilms and its controlled release, upon exposure of the nanofilms to an aqueous α-amylase solution, are demonstrated. The highly cytocompatible nature of the film-forming and -degrading conditions is assessed in the c-ST/ALG-shell formation and degradation of S. cerevisiae. We envisage that the cytocompatible, enzymatic degradation of c-ST-based nanofilms paves the way for developing advanced biomedical devices with programmed dissolution in vivo.

Changes in the morphology of the triangular fibrocartilage complex (TFCC) on magnetic resonance arthrography related to disruption of ulnar foveal attachment.

OBJECTIVE: To assess whether a proximal ligamentous component (PLC) of the triangular fibrocartilage complex (TFCC) with a distally prolapsing morphology is associated with the presence of a TFCC foveal tear on arthroscopy. METHODS: One-hundred thirty-two patients (134 wrists) who underwent MR arthrography and subsequent wrist arthroscopy between September 2014 and March 2018 were retrospectively evaluated. The degree of distal PLC prolapse was measured on coronal MR arthrography using the height-to-length ratio (HLR). Subjects' demographics, ulnar variance, presence of a degenerative TFCC tear, and ulnar styloid nonunion were assessed. The association between specific variables and the presence of a foveal tear was investigated. RESULTS: A TFCC foveal tear was identified in a total of 101 of 134 wrists examined by arthroscopy. Univariable analysis showed that the HLR of the PLC was significantly greater in the foveal tear group compared with the intact fovea group (44.6 vs. 38.9%, respectively, p < 0.001). Multivariable analysis showed that HLR was positively associated with a foveal tear (odds ratio [OR], 1.211; p < 0.001). The estimated cut-off value of the HLR was 41% (area under the curve [AUC] 0.77). CONCLUSIONS: PLCs with a distal prolapse pattern and large HLR are associated with TFCC foveal tears. The HLR of the PLC measured on coronal MR images can therefore be used as an additional predictor of tears of the foveal attachment of the TFCC.

Functional Outcomes Are Similar After Early and Late Arthroscopic One-Tunnel Transosseous Repair of Triangular Fibrocartilage Complex Foveal Tears.

PURPOSE: To compare outcomes at different time periods following arthroscopic triangular fibrocartilage complex (TFCC) transosseous foveal repair within 6 months, between 6 and 12 months, and more than 12 months from injury. METHODS: Consecutive patients treated with arthroscopic TFCC foveal repair using the uniform one-tunnel transosseous suture technique by a surgeon from 2014 to 2017 were retrospectively reviewed. The patients were assigned to 1 of 3 groups according to time between injury and surgery. Pain visual analog scale (VAS); grip strength; modified Mayo wrist score (MMWS); Quick disabilities of the arm, shoulder, and hand (QuickDASH) score; and distal radioulnar joint stability were assessed at minimum 2 years postoperatively, along with minimal clinically important difference, and overall patient satisfaction. RESULTS: This study cohort consisted of 80 patients: group A (<6 months, n = 38), group B (6-12 months, n = 20), and group C (>12 months, n = 22). No differences were found among groups in VAS, grip strength, and MMWS and QuickDASH. Overall, patients exhibited significant functional improvement at 2 years (VAS: 3-0, P < .001; grip strength: 77.1%-95.6%, P < .001; MMWS: 65-90, P < .001, QuickDASH: 20.5-4.5, P < .001). Median changes in outcome variables and the proportion of patients achieving minimal clinically important difference for the QuickDASH were similar among groups. Seventy-eight patients (97%) achieved distal radioulnar joint stability, and 70 patients (87%) were satisfied with treatment. CONCLUSIONS: Although this current study has insufficient statistical power, the available data suggest that patients with a TFCC foveal tear who underwent arthroscopic transosseous repair surgery more than 12 months after injury could expect to experience similar functional improvement compared with patients who underwent surgery within 6 months or between 6 and 12 months following injury. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Thickness-Tunable Eggshell Membrane Hydrolysate Nanocoating with Enhanced Cytocompatibility and Neurite Outgrowth.

The eggshell membrane is one of the easily obtainable natural biomaterials, but has been neglected in the biomaterial community, compared with marine biomaterials and discarded as a food waste. In this work, we utilized the ESM hydrolysate (ESMH), which was obtained by the enzymochemical method, as a bioactive functional material for interfacial bioengineering, exemplified by thickness-tunable, layer-by-layer (LbL) nanocoating with the Fe(III)-tannic acid (TA) complex. [Fe(III)-TA/ESMH] LbL films, ending with the ESMH layer, showed great cytocompatiblility with HeLa cells and even primary hippocampal neuron cells. More importantly, the films were found to be neurochemically active, inducing the acceleration of neurite outgrowth for the long-term neuron culture. We believe that the ability for building cytocompatible ESMH films in a thickness-tunable manner would be applicable to a broad range of different nanomaterials in shape and size and would be utilized with multimodal functionalities for biomedical applications, such as bioencapsulation, theranostics, and regenerative medicine.

Latent heat storage biocomposites of phase change material-biochar as feasible eco-friendly building materials.

One approach to enhance the energy efficiency of buildings is the integration of construction materials of latent heat storage biocomposites, which are prepared by vacuum impregnating the phase change material into biochar. Biochar is used because it is highly utilized and environmentally-friendly, and the selected phase change materials are fatty acid type which are bio-based material and have a low risk of depletion. Experimental results showed that latent heat storage biocomposite possesses excellent exudation and thermal stability as characterized by 0.1727 W/mK of thermal conductivity comparable to that for a gypsum board, and good chemical compatibility as its amount of latent heat tends to decrease as compared with that of pure phase change material. Results of the numerical analysis showed further that latent heat storage biocomposite efficiently reduced the maximum energy consumption of reference building models by 531.31 kWh per year. Thus, both results validate the claim that latent heat storage biocomposite is a promising building material.

Radiographic prediction of lunate morphology in Asians using plain radiographic and capitate-triquetrum distance analyses: reliability and compatibility with magnetic resonance arthrography (MRA) findings.

BACKGROUND: The purpose of this study was to examine the reliability of plain radiographic methods of determining the lunate type and its compatibility with magnetic resonance arthrography (MRA) findings. METHODS: Plain radiographs of a total of 150 wrists were reviewed by three observers. Lunate types were evaluated using both conventional posteroanterior (PA) radiographic analysis and the capitate-triquetrum distance (CTD) analysis. Cohen kappa and Fleiss kappa statistics were used to estimate intra- and inter-observer reliabilities. Compatibility with the MRA findings, as assessed by each observer, was investigated. RESULTS: The overall intra-observer reliability was 0.517 for the analysis and 0.589 for the CTD analysis. The overall inter-observer agreement was 0.448 for the PA radiographic analysis and 0.581 for the CTD analysis. The PA radiographic analysis and MRA findings for the detection of medial lunate facets were compatible in 119 of the 150 patients (79.3%). Twenty-eight (90.3%) of the 31 incompatible wrists had a medial facet on MRA (Type II), which was not detected in the PA radiographic analysis. In the CTD analysis, the results for 27 of 29 Type II lunates (93.1%) and 39 of 45 Type I lunates (86.7%) were compatible with the MRA. CONCLUSIONS: This study suggests that predicting the lunate type by plain radiographs alone is insufficient, as both radiographic analyses showed moderate intra- and inter-observer reliabilities. Although both radiographic analyses showed good compatibility with the MRA for Type II lunates, clinicians should be alert to undetected medial facets in Type I lunates on PA radiographic analysis.

Dorsal transosseous reduction and locking plate fixation for articular depressed middle phalangeal base fracture.

PURPOSE: An articular depressed fragment at the base of the middle phalanx can be an obstacle to congruent reduction and stable fixation. This study assessed the outcomes of a transosseous reduction technique combined with locking plate fixation for the treatment of articular depressed middle phalangeal base fracture. METHODS: Between 2015 and 2017, seven patients (eight fingers) with intraarticular comminuted middle phalangeal base fracture were included in this study. Mean follow-up was 19 months (range 12-30 months). All patients showed depression of the articular fragment on sagittal computed tomography (CT) scan and were treated with a transosseous reduction technique and dorsal locking plate fixation. Radiographic evaluation was performed to ensure restoration of a concentric articular surface postoperatively. Total active range of motion (TAM) of the finger, grip strength, and the quick Disabilities of the Arm, Shoulder and Hand (quick DASH) score were evaluated at the last follow-up. Complications were also assessed. RESULTS: All fractures obtained bony union with a concentric joint. There was no significant loss of reduction during the follow-up period. The mean active proximal interphalangeal (PIP) joint and distal interphalangeal joint motion arcs at follow-up were 89° and 61°, respectively. Mean TAM of the affected finger and mean grip strength were 94% (range 80-100%) and 94% (range 86-100%) of the contralateral side, respectively. Mean quick DASH score was 2.3 (range 0-9.1). All patients returned to work. No surgery-related complications occurred. CONCLUSIONS: This technique provides satisfactory restoration of articular congruence and enables the early joint mobilization of articular depression-type fractures of the base of the middle phalanx. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic, level IV.

Salt-Induced, Continuous Deposition of Supramolecular Iron(III)-Tannic Acid Complex.

One-step assembly of iron(III)-tannic acid (Fe3+-TA) complex forms nanothin (∼10 nm) films on various substrates within minutes. In this deposition scheme, however, the film does not grow continuously over time even though Fe3+-TA complex is still abundant in the coating solution. In this paper, we report that the salt addition dramatically changes the one-off coating characteristic to continuous one, and each salt has its optimum concentration ( CMFT) that produces maximum film thickness. For detailed investigation of the salt effects, we employed various salts, including LiCl, NaCl, KCl, CaCl2, SrCl2, BaCl2, NaBr, and NaNO3, and found that only cations played an important role in the continuous deposition of the Fe3+-TA complex, with smaller CMFT values for the cations of higher valency and larger size. On the basis of the results, we suggested that the positively charged cations screened the negative surface charges of Fe3+-TA complex particles, leading to coagulation and continuous deposition, further supported by the ζ-potential measurement and time-resolved dynamic light-scattering analysis.

Accelerated Development of Hippocampal Neurons and Limited Adhesion of Astrocytes on Negatively Charged Surfaces.

This work examines the development of primary neurons and astrocytes on thoroughly controlled functional groups. Negatively charged surfaces presenting carboxylate (COO-) or sulfonate (SO3-) groups prove beneficial to neuronal behavior, in spite of their supposed repulsive electrostatic interactions with cellular membranes. The adhesion and survival of primary hippocampal neurons on negatively charged surfaces are comparable to or slightly better than those on positively charged (poly-d-lysine-coated) surfaces, and neuritogenesis and neurite outgrowth are accelerated on COO- and SO3- surfaces. Moreover, such favorable influences of the negatively charged surfaces are only seen in neurons but not for astrocytes. Our results indicate that the in vitro developmental behavior of primary hippocampal neurons is sophisticatedly modulated by angstrom-sized differences in chemical structure or the charge density of the surface. We believe that this work provides new implications for understanding neuron-material interfaces as well as for establishing new ways to fabricate neuro-active surfaces.