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•We designed fully bioresorbable FF nanotube-based piezoelectric nanocomposite.•Self-assembled FF nanotubes provide high piezoelectric responses.•FEM simulation enabled rational ...selection of polymer matrices of FF nanotubes.•FF-based nanocomposites generate local piezoelectricity upon cell activity.•The local piezoelectricity can manipulate cell alignment and proliferation.
Here we propose a material design for nanocomposites of self-assembled diphenylalanine (FF) nanotubes with bioresorbable polymer matrices to achieve a flexible and mechanically durable bio-piezoelectric nanogenerator (bio-PENG). The piezoelectric property of the nanocomposite membranes demonstrates a normal-like distribution in accordance with Young’s modulus of the polymer matrices. Attributed to the high conformability between polyvinyl alcohol (PLA) and FF nanotubes, the PLA-based nanocomposite bio-PENG exhibits high electrical output performance, reaching an output voltage of 2.8 V and power density of 2.6 μW cm−2. Moreover, the bio-PENG shows stable energy-generating performance for over 1000 operating cycles. Benefiting from the high piezoelectric property, the nanocomposite can manipulate cell activities including alignment and proliferation. The results of the simulation using the finite element method (FEM) confirm that the nanocomposite can generate piezoelectricity through mechanical strain caused by free migration of cells. In vitro demonstration shows that cell migration-induced piezoelectricity allows for the manipulation of cell alignment and proliferation. Thus, our material design of FF nanotube-based nanocomposites presents a promising option for bioresorbable energy harvesters that will be widely available in biomedical applications.
STUDY DESIGN.A retrospective study.
OBJECTIVE.To determine the incidence and risk factors of adjacent segment disease (ASD) requiring surgery among patients previously treated with spinal fusion for ...degenerative lumbar disease and to compare the survivorship of adjacent segment according to various risk factors including comparison of fusion methodsposterior lumbar interbody fusion (PLIF) versus posterolateral fusion (PLF).
SUMMARY OF BACKGROUND DATA.One of the major issues after lumbar spinal fusion is the development of adjacent segment disease. Biomechanically, PLIF has been reported to be more rigid than PLF, and therefore, patients who undergo PLIF are suspected to experience a higher incidence of ASD than those who underwent PLF. There have been many studies analyzing the risk factors of ASD, but we are not aware of any study comparing PLIF with PLF in incidence of ASD requiring surgery.
METHODS.A consecutive series of 490 patients who had undergone lumbar spinal fusion of 3 or fewer segments to treat degenerative lumbar disease was identified. The mean age at index operation was 53 years, and the mean follow-up period was 51 months (12–236 mo). The number of patients treated by PLF and PLIF were 103 and 387, respectively. The incidence and prevalence of revision surgery for ASD were calculated by Kaplan-Meier method. For risk factor analysis, we used log-rank test and Cox regression analysis with fusion methods, sex, age, number of fused segments, and presence of laminectomy adjacent to index fusion.
RESULTS.After index spinal fusion, 23 patients (4.7%) had undergone additional surgery for ASD. Kaplan-Meier analysis predicted a disease-free survival rate of adjacent segments in 94.2% of patients at 5 years and 89.6% at 10 years after the index operation. In the analysis of risk factors, PLIF was associated with 3.4 times higher incidence of ASD requiring surgery than PLF (P = 0.037). Patients older than 60 years at the time of index operation were 2.5 times more likely to undergo revision operation than those younger than 60 years (P = 0.038). There were no significant differences in survival rates of the adjacent segment according to sex, preoperative diagnosis, number of fused segments, and concomitant laminectomy to adjacent segment.
CONCLUSION.It was predicted that 10% of patients would undergo additional surgery for treating ASD within 10 years after index lumbar fusion. In this study, PLIF showed higher incidence of ASD than did PLF. Patient age greater than 60 years was another independent risk factor. Surgeons should carefully consider these factors at the time of surgical planning of lumbar fusion.Level of Evidence3
Implantable medical devices (IMDs) provide practical approaches to monitor physiological parameters, diagnose diseases, and aid treatment. However, device installation, maintenance, and long‐term ...implantation increase the risk of infection with conventional IMDs. Therefore, medical devices with biocompatibility, controllability, and miniaturization are highly demandable. An ultrasound‐driven, biodegradable, and injectable triboelectric nanogenerator (I‐TENG) is demonstrated to reduce the risks of implant‐related injuries and infections. The injection can be given by subcutaneous injection with a needle to minimize the implantation incision. The stable output of I‐TENG is driven by ultrasound (20 kHz, 1 W cm−2), with a voltage of 356.8 mV and current of 1.02 µA during in vivo studies and an electric field of about 0.92 V mm−1 during ex vivo experiments. The cell scratch and proliferation assays showed that the delivered electric field effectively increased cell migration and proliferation, indicating a significant potential to accelerate healing with electricity.
Ultrasound‐driven injectable and fully biodegradable triboelectric nanogenerators (I‐TENGs) are demonstrated to produce electricity in a body. Additionally, I‐TENGs provide a continuous alternating electric field that significantly enhances cell migration and proliferation, indicating the great potential to promote wound healing. It is suggested that the I‐TENG provides a new energy solution for developing fully biodegradable implantable medical devices with miniaturization, integration, and biocompatibility.
Glucagon-like peptide-1 (GLP-1) receptor participates in the control of bone resorption in GLP-1 knockout mice. Also, GLP-1 induces an insulin- and parathyroid hormone-independent osteogenic action ...through osteoclasts and osteoblasts in insulin-resistant and type 2 diabetic rats. Osteocytes are now considered central to bone homeostasis. A secreted product of osteocytes, sclerostin, inhibits bone formation. However, the effect of GLP-1 on osteocytes remains unclear. Therefore, we investigated the effect of GLP-1 on bone mineral density (BMD), and the cellular and molecular mechanisms associated with osteocytes.
We investigated the presence of GLP-1 receptors in osteocyte-like MLO-Y4 cells and osteocytes of rat femurs through RT-PCR, Western blot and confocal microscopy, and investigated the effect of exendin-4 on the expression of mRNA (by quantitative real-time RT-PCR) and protein (by Western blot) of SOST/sclerostin in osteocyte-like MLO-Y4 cells during culture under normal or high-glucose (30mM) conditions, and measured circulating levels of sclerostin, osteocalcin, and tartrate-resistant alkaline phosphatase (TRAP) 5b and femoral BMD in type 2 diabetic OLETF rats treated with exendin-4.
GLP-1 receptor was present on MLO-Y4 cells and osteocytes of rat femurs. Exendin-4 reduced the mRNA expression and protein production of SOST/sclerostin under normal or high-glucose conditions in MLO-Y4 cells. Exendin-4 reduced serum levels of sclerostin, increased serum levels of osteocalcin, and increased femoral BMD in type 2 diabetic OLETF rats.
These findings suggest that exendin-4 might increase BMD by decreasing the expression of SOST/sclerostin in osteocytes in type 2 diabetes.
Immediate breast reconstruction with tissue expander in breast cancer patients who were expected to receive adjuvant therapy, such as chemotherapy or radiotherapy, has been a topic of debate. ...Postoperative complications from tissue expander procedures can delay the timing of adjuvant treatment and subsequently increase the probability of recurrence. The purpose of this study was to identify the impact of chemotherapy and radiotherapy on postoperative complications in patients who underwent immediate reconstruction (IR) using tissue expander.
We conducted a retrospective study of 1081 breast cancer patients who underwent mastectomy and IR using tissue expander insertion between 2012 and 2017 in Samsung Medical Center. The patients were divided into two groups based on complications (complication group vs. no complication group). Complication group was regarded to have surgical removal or conservative treatment based on clinical findings such as infection, capsular contracture, seroma, hematoma, rupture, malposition, tissue viability, or cosmetic problem. The complication group had 59 patients (5.5%) and the no complication group had 1022 patients (94.5%).
In univariate analysis, adjuvant radiotherapy and adjuvant chemotherapy were significantly associated with postoperative complications. In multivariate analysis, however, only higher pathologic N stage was significantly associated with postoperative complications (p < 0.001). Chemotherapy (p = 0.775) or radiotherapy (p = 0.825) were not risk factors for postoperative complications.
IR with tissue expander after mastectomy may be a treatment option even when the patients are expected to receive adjuvant chemotherapy or radiotherapy. These results will aid patients who are concerned about the complications of IR caused by chemotherapy or radiotherapy determine whether or not to have IR.
Patients were selected and registered retrospectively, and medical records were evaluated.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The efficacy of tranexamic acid (TXA) has been reported in breast surgery; however, its application and duration have varied across studies. This study aimed to assess the early postoperative ...outcomes of rinsing the breast pocket with TXA during prepectoral prosthetic breast reconstruction using an acellular dermal matrix (ADM).
A retrospective chart review was conducted in consecutive patients who underwent immediate prosthetic prepectoral reconstruction between August 2021 and December 2022. For cases performed during the earlier part of the study period (up to April 2022), TXA was not administered (non-TXA group), whereas those performed after April 2022 received topical TXA application during surgery (TXA group). Postoperative outcomes including hematoma, seroma, drainage volume, and drain maintenance duration were compared between the two groups using propensity score matching (PSM).
A total of 674 breasts were analyzed; 280 in the TXA group and 394 were in the non-TXA group. There were 251 breasts in each group after PSM, and their characteristics were similar. The incidence of hematoma in the first 24 hours and total drain output were significantly lower in the TXA group than the non-TXA group. In cases of direct-to-implant cases, the TXA group showed a significantly lower seroma rate.
Rinsing the breast pocket with TXA can potentially reduce the occurrence of hematoma and decrease drain output in prepectoral ADM-assisted prosthetic breast reconstruction. Moreover, this approach may be beneficial in lowering the incidence of seroma in direct-to-implant reconstruction.
Abstract
Spine surgeons often encounter cases of delayed postoperative spinal infection (PSI). Delayed-onset PSI is a common clinical problem. However, since many studies have investigated acute ...PSIs, reports of delayed PSI are rare. The purpose of this study was to compare the clinical features, treatment course, and prognosis of delayed PSI with acute PSI.
Ninety-six patients diagnosed with postoperative spinal infection were enrolled in this study. Patients were classified into 2 groups: acute onset (AO) within 90 days (n = 73) and delayed onset (DO) after 90 days (n = 23). The baseline data, clinical manifestations, specific treatments, and treatment outcomes were compared between the 2 groups.
The history of diabetes mellitus (DM) and metallic instrumentation at index surgery were more DO than the AO group. The causative organisms did not differ between the 2 groups. Redness or heat sensation around the surgical wound was more frequent in the AO group (47.9%) than in the DO group (21.7%) (
P
= .02). The mean C-reactive protein levels during infection diagnosis was 8.9 mg/dL in the AO and 4.0 mg/dL in the DO group (
P
= .02). All patients in the DO group had deep-layer infection. In the DO group, revision surgery and additional instrumentation were required, and the duration of parenteral antibiotic use and total antibiotic use was significantly longer than that in the AO group. Screw loosening, disc space collapse, and instability were higher in the DO group (65.2%) than in the AO group (41.1%) (
P
= .04). However, the length of hospital stay did not differ between the groups.
Delayed-onset PSI requires more extensive and longer treatment than acute-onset surgical site infection. Clinicians should try to detect the surgical site infection as early as possible.
Purpose
To investigate the impact of immediate breast reconstruction (iBR) on patients treated with post-mastectomy radiation therapy (PMRT) using propensity score matching (PSM).
Methods
After a ...retrospective review of patients treated with PMRT between 2008 and 2017, we included 153 patients who underwent iBR and 872 patients who did not undergo iBR. Among the 153 patients who underwent iBR, 34 received one-stage iBR with autologous tissue and 119 received two-stage iBR. Conventional fractionated PMRT with a total dose of 50–50.4 Gy in 25–28 fractions was performed in all patients. Propensity scores were calculated via logistic regression.
Results
Patients who underwent iBR were younger, had early stage disease, and had more frequent hormone receptor-positive tumor than those who did not undergo iBR. After PSM, 127 patients from each group with well-balanced characteristics were selected. With a median follow-up of 67.5 months, iBR led to better 6-year disease-free survival rates compared to no iBR before PSM (84.8% vs. 71.4%,
p
= 0.003); after PSM, there was no significant difference (84.8% vs. 75.5%,
p
= 0.130). On multivariable analysis in the matched cohort, iBR was not associated with inferior disease-free survival (hazard ratio, 0.67;
p
= 0.175). In the sensitivity analysis, iBR was not associated with a lower disease-free survival across all prognostic groups. The 5-year cumulative incidence of iBR failure was 15.0%.
Conclusion
In patients with adverse pathologic factors planning to receive PMRT, iBR did not compromise oncologic outcomes. In addition, iBR can be considered in patients treated with PMRT with several clinicopathologic risk factors.
Epilepsy is a prevalent neurological disorder characterized by recurrent seizures. Validamycin A (VA) is an antibiotic fungicide that inhibits trehalase activity and is widely used for crop ...protection in agriculture. In this study, we identified a novel function of VA as a potential anti-seizure medication in a zebrafish epilepsy model. Electroencephalogram (EEG) analysis demonstrated that VA reduced pentylenetetrazol (PTZ)-induced seizures in the brains of larval and adult zebrafish. Moreover, VA reduced PTZ-induced irregular movement in a behavioral assessment of adult zebrafish. The developmental toxicity test showed no observable anatomical alteration when the zebrafish larvae were treated with VA up to 10 µM within the effective range. The median lethal dose of VA in adult zebrafish was > 14,000 mg/kg. These results imply that VA does not demonstrate observable toxicity in zebrafish at concentrations effective for generating anti-seizure activity in the EEG and alleviating abnormal behavior in the PTZ-induced epileptic model. Furthermore, the effectiveness of VA was comparable to that of valproic acid. These results indicate that VA may have a potentially safer anti-seizure profile than valproic acid, thus offering promising prospects for its application in agriculture and medicine.
Large‐scale 2D single‐crystalline copper nanoplates (Cu NPLs) are synthesized by a simple hydrothermal method. The combination of a mild reductant, stabilizer, and shape modifier allows the ...dimensional control of the Cu nanocrystals from 1D nanowires (NWs) to 2D nanoplates. High‐resolution transmission electron microscopy (HR‐TEM) reveals that the prepared Cu NPLs have a single‐crystalline structure. From the X‐ray photoelectron spectroscopy (XPS) analysis, it is found that iodine plays an important role in the modification of the copper nanocrystals through the formation of an adlayer on the basal plane of the nanoplates. Cu NPLs with an average edge length of 10 μm are successfully synthesized, and these Cu NPLs are the largest copper 2D crystals synthesized by a solution‐based process so far. The application of the metallic 2D crystals as a semitransparent electrode proves their feasibility as a conductive filler, exhibiting very low sheet resistance (0.4 Ω ▫−1) compared to Cu NWs and a transmittance near 75%. The efficient charge transport is due to the increased contact area between each Cu NPL, i.e., so‐called plane contact (2D electrical contact). In addition, this type of contact enhances the current‐carrying capability of the Cu NPL electrodes, implying that the large‐size Cu NPLs are promising conductive fillers for printable electrode applications.
Large‐scale 2D single‐crystalline copper nanoplates (Cu NPLs) are synthesized by a simple hydrothermal method. The synthesized Cu NPLs have an average edge length of 10 µm. The application of the metallic 2D crystals as a semitransparent electrode proves their feasibility as a conductive filler.
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