Evaluation of the suitability of using ArtiSential in various renal surgery: IDEAL stage 1 study.

BACKGROUND: ArtiSential, a new articulating laparoscopic instruments, addresses the limited movement associated with conventional laparoscopic instruments. This study was conducted to assess the clinical effectiveness of ArtiSential in detailed steps of various renal surgery. METHODS: This study was approved by the Institutional Review Board of our institution and registered on the Clinical Research Information Service site of the Korea Disease Control and Prevention Agency. Participants meeting all inclusion and exclusion criteria were included in the clinical trial and underwent renal surgery. The clinical effectiveness of ArtiSential was assessed in terms of the feasibility and objective and subjective parameters across 9 detailed steps. RESULTS: Of the 15 potential candidates enrolled from October 2021 to November 2021, 1 patient dropped out due to anaphylaxis from an anesthetic agent, and 14 patients underwent laparoscopic surgery using ArtiSential. Of the 14 patients, 2 patients were converted to laparoscopic surgery using straight-shaped instruments due to the ischemia time exceeding 30 min, and 1 patient due to excessive bleeding. The feasibility for most steps was more than 90%, except the renorrhaphy step. The median total operation time and ischemia time were 161 and 23 min, respectively. The median estimated blood loss was 58.5 mL. Two cases of venous injury occurred during renal pedicle dissection step. The accuracy of the procedure judged by reviewers and usability judged by the operator were acceptable in all steps. The surgeon's quantitatively measured stress score was the highest during renorrhaphy step. CONCLUSIONS: Laparoscopic surgery using ArtiSential is feasible for most steps except the renorrhaphy step. The difficulty of performing renorrhaphy is attributed to prolonged ischemia time, which could be addressed by overcoming the learning curve. TRIAL REGISTRATION: Clinical Research Information Service site of the Korea Disease Control and Prevention Agency, KCT0006532. Registered 03/09/2021, https://cris.nih.go.kr/cris/search/detailSearch.do?seq=24071 .

The role of PIEZO ion channels in the musculoskeletal system.

PIEZO1 and PIEZO2 are mechanosensitive cation channels that are highly expressed in numerous tissues throughout the body and exhibit diverse, cell-specific functions in multiple organ systems. Within the musculoskeletal system, PIEZO1 functions to maintain muscle and bone mass, sense tendon stretch, and regulate senescence and apoptosis in response to mechanical stimuli within cartilage and the intervertebral disc. PIEZO2 is essential for transducing pain and touch sensations as well as proprioception in the nervous system, which can affect musculoskeletal health. PIEZO1 and PIEZO2 have been shown to act both independently as well as synergistically in different cell types. Conditions that alter PIEZO channel mechanosensitivity, such as inflammation or genetic mutations, can have drastic effects on these functions. For this reason, therapeutic approaches for PIEZO-related disease focus on altering PIEZO1 and/or PIEZO2 activity in a controlled manner, either through inhibition with small molecules, or through dietary control and supplementation to maintain a healthy cell membrane composition. Although many opportunities to better understand PIEZO1 and PIEZO2 remain, the studies summarized in this review highlight how crucial PIEZO channels are to musculoskeletal health and point to promising possible avenues for their modulation as a therapeutic target.

Solo-surgeon pure laparoscopic donor nephrectomy using passive camera holder: IDEAL stage 2a study.

BACKGROUND: Solo-surgery can be defined as a practice of a surgeon operating alone using a camera holder, without other surgical members except for a scrub nurse. This study was designed to evaluate the feasibility and safety of solo-surgeon pure laparoscopic donor nephrectomy. METHODS: The study protocol was approved by the Institutional Review Board of Asan Medical Center, Seoul, Korea. The brief study protocol was registered on the Clinical Research Information Service site of the Korea Centers for Disease Control and Prevention. Candidates fulfilling all inclusion and exclusion criteria were enrolled in the clinical trial and underwent solo-surgeon pure laparoscopic donor nephrectomy. The feasibility was assessed by the proportion of subjects who could undergo solo-surgeon pure laparoscopic donor nephrectomy without difficulty. The perioperative complications were identified to assess the safety of solo-surgeon pure laparoscopic donor nephrectomy. RESULTS: Of the 47 potential candidates from November 2018 to August 2019, 40 were enrolled in the clinical trial and seven excluded due to declining participation. The feasibility of solo-surgeon pure laparoscopic donor nephrectomy was 100%, without an occasion of any difficulty requiring conversion to the human assisted pure laparoscopic donor nephrectomy. Fourteen intraoperative complications occurred in 10 patients. The most common intraoperative complication was spleen injury. Two of three cases classified as the Satava classification grade II were due to the incomplete stapling of endoscopic stapler. Seventy-eight postoperative complications occurred in 34 patients. The most common postoperative complication was nausea/vomiting and followed by aspartate aminotransferase/alanine aminotransferase elevation. Most postoperative complication was independent of the solo-surgery itself. CONCLUSIONS: Solo-surgeon pure laparoscopic donor nephrectomy using passive camera holder is technically feasible. In terms of safety, it is necessary to adjust the scope of surgery performed alone. Trial Registration CRIS, KCT0003458. Registered 30/01/2019, Retrospectively registered, https://cris.nih.go.kr/cris/search/detailSearch.do/15868 .

Engineering Hyaluronic Acid for the Development of New Treatment Strategies for Osteoarthritis.

Osteoarthritis (OA) is a degenerative joint disease that is characterized by inflammation of the joints, degradation of cartilage, and the remodeling of other joint tissues. Due to the absence of disease-modifying drugs for OA, current clinical treatment options are often only effective at slowing down disease progression and focus mainly on pain management. The field of tissue engineering has therefore been focusing on developing strategies that could be used not only to alleviate symptoms of OA but also to regenerate the damaged tissue. Hyaluronic acid (HA), an integral component of both the synovial fluid and articular cartilage, has gained widespread usage in developing hydrogels that deliver cells and biomolecules to the OA joint thanks to its biocompatibility and ability to support cell growth and the chondrogenic differentiation of encapsulated stem cells, providing binding sites for growth factors. Tissue-engineering strategies have further attempted to improve the role of HA as an OA therapeutic by developing diverse modified HA delivery platforms for enhanced joint retention and controlled drug release. This review summarizes recent advances in developing HA-based hydrogels for OA treatment and provides additional insights into how HA-based therapeutics could be further improved to maximize their potential as a viable treatment option for OA.

Evaluation of tissue integration of injectable, cell-laden hydrogels of cocultures of mesenchymal stem cells and articular chondrocytes with an ex vivo cartilage explant model.

This study investigated the chondrogenic activity of encapsulated mesenchymal stem cells (MSCs) and articular chondrocytes (ACs) and its impact on the mechanical properties of injectable poly(N-isopropylacrylamide)-based dual-network hydrogels loaded with poly( l -lysine) (PLL). To this effect, an ex vivo study model was employed to assess the behavior of the injected hydrogels-specifically, their surface stiffness and integration strength with the surrounding cartilage. The highest chondrogenic activity was observed from AC-encapsulated hydrogels, while the effect of PLL on MSC chondrogenesis was not apparent from biochemical analyses. Mechanical testing showed that there were no significant differences in either surface stiffness or integration strength among the different study groups. Altogether, the results suggest that the ex vivo model can allow further understanding of the relationship between biochemical changes within the hydrogel and their impact on the hydrogel's mechanical properties.

Identifying Structural Determinants of Product Specificity in Leishmania major Farnesyl Diphosphate Synthase.

Farnesyl diphosphate synthase (FPPS) is an isoprenoid chain elongation enzyme that catalyzes the sequential condensation of dimethylallyl diphosphate (C5) with isopentenyl diphosphate (IPP; C5) and the resulting geranyl diphosphate (GPP; C10) with another molecule of IPP, eventually producing farnesyl diphosphate (FPP; C15), which is a precursor for the biosynthesis of a vast majority of isoprenoids. Previous studies of FPPS have highlighted the importance of the structure around the hydrophobic chain elongation path in determining product specificity. To investigate what structural features define the final chain length of the product in FPPS from Leishmania major, we designed and expressed six mutants of LmFPPS by replacing small amino acids around the binding pocket with bulky residues. Using enzymatic assays, binding kinetics, and crystallographic studies, we analyzed the effects of these mutations on the activity and product specificity of FPPS. Our results revealed that replacement of Thr-164 with tryptophan and phenylalanine completely abolished the activity of FPPS. Intriguingly, the T164Y substitution displayed dual product specificity and produced a mixture GPP and FPP as final products, with an activity for FPP synthesis that was lower than that of the wild-type enzyme. These data indicate that Thr-164 is a potential regulator of product specificity.

Biomacromolecules for Tissue Engineering: Emerging Biomimetic Strategies.

Biomacromolecules used for tissue engineering must possess either inherent biochemical cues for tissue regeneration or be chemically modified to incorporate bioactive, tissue-specific moieties. To this end, many strategies have emerged recently in the field to both utilize novel bioinspired macromolecules for tissue engineering and apply bioconjugation strategies for the functionalization of biomacromolecules with tissue-specific cues and other biological properties of interest. Furthermore, biomacromolecules have been processed into more highly biomimetic and clinically deliverable scaffold and hydrogel systems using 3D printing and the fabrication of in situ forming hydrogels, respectively. To support these advances, tissue engineers have also pursued greater spatiotemporal control over macromolecular bioactivity and the modulation of scaffold and hydrogel properties in response to both physiological and external stimuli. This Perspective thus highlights a few notable advances and techniques in the usage of biomacromolecules for tissue engineering applications, including new bioinspired macromolecules, advanced hydrogel and scaffold fabrication techniques, and spatiotemporal control over biomacromolecule constructs.

Hemodynamic Effects on Systemic Blood Flow and Ductal Shunting Flow after Loading Dose of Intravenous Caffeine in Preterm Infants according to the Patency of Ductus Arteriosus.

BACKGROUND: In preterm infants, caffeine citrate is used to stimulate breathing before they are weaned from mechanical ventilation and to reduce the frequency of apnea. In recent studies, effects of caffeine on the cardiovascular system have been emphasized in preterm infants with patent ductus arteriosus (PDA). METHODS: This study aimed to assess the short-term hemodynamic effects on systemic blood flow and ductal shunting flow after loading standard doses of intravenous caffeine in preterm infants. Echocardiographic studies were performed by a single investigator, before and at 1 hour and 4 hours after an intravenous infusion of a loading dose as 20 mg/kg caffeine citrate for 30 minutes. RESULTS: In 25 preterm infants with PDA, left ventricular output decreased progressively during 4 hours after caffeine loading. Superior vena cava (SVC) flow decreased and ductal shunting flow increased at 1 hour and then recovered at 4-hour to baseline values. A diameter of PDA significantly decreased only at 4-hour after caffeine loading. There were no significant changes of these hemodynamic parameters in 29 preterm infants without PDA. CONCLUSION: In preterm infants with PDA, a standard intravenous loading dose of 20 mg/kg caffeine citrate was associated with increasing ductal shunting flow and decreasing SVC flow (as a surrogate for systemic blood flow) 1 hour after caffeine loading, however, these hemodynamic parameters recovered at 4 hours according to partial constriction of the ductus arteriosus. Close monitoring of hemodynamic changes would be needed to observe the risk for pulmonary over-circulation or systemic hypo-perfusion due to transient increasing ductal shunting flow during caffeine loading in preterm infants with PDA.

Tuning the Response of Synthetic Mechanogenetic Gene Circuits Using Mutations in TRPV4.

Conventional gene therapy approaches for drug delivery generally rely on constitutive expression of the transgene and thus lack precise control over the timing and magnitude of delivery. Synthetic gene circuits with promoters that are responsive to user-defined stimuli can provide a molecular switch that can be utilized by cells to control drug production. Our laboratory has previously developed a mechanogenetic gene circuit that can deliver biological drugs, such as interleukin-1 receptor antagonist (IL-1Ra), on-demand through the activation of Transient receptor potential family, vanilloid 4 (TRPV4), a mechanosensory ion channel that has been shown to be activated transiently in response to physical stimuli such as physiological mechanical loading or hypo-osmotic stimuli. The goal of this study was to use mutations in TRPV4 to further tune the response of this mechanogenetic gene circuit. Human iPSC-derived chondrocytes harboring targeted gain-of-function mutations of TRPV4 were chondrogenically differentiated. Both mutants-V620I and T89I-showed greater total IL-1Ra production compared with wild type following TRPV4 agonist treatment, as well as mechanical or osmotic loading, but with altered temporal dynamics. Gene circuit output was dependent on the degree of TRPV4 activation secondary to GSK101 concentration or strain magnitude during loading. V620I constructs secreted more IL-1Ra compared with T89I across all experimental conditions, indicating that two mutations that cause similar functional changes to TRPV4 can result in distinct circuit activation profiles that differ from wild-type cells. In summary, we successfully demonstrate proof-of-concept that point mutations in TRPV4 that alter channel function can be used to tune the therapeutic output of mechanogenetic gene circuits.

Laparoscopic renal surgery using multi degree-of-freedom articulating laparoscopic instruments in a porcine model.

PURPOSE: We evaluated the performance of a new multi-degree-of-freedom articulating laparoscopic instrument, ArtiSential, and compared it with that of a straight-shaped instrument and the da Vinci surgical system, in renal surgery using porcine model. MATERIALS AND METHODS: Nine female Yorkshire pigs were equally divided into three groups. The three groups were compared at each surgical step in terms of objective and subjective parameters. RESULTS: The median operative times for renal pedicle clamping and ureter dissection were significantly shorter in ArtiSential group than robotic group (1.3 min vs. 4.7 min, p=0.002; 8.1 min vs. 11.1 min, p=0.015). The median operative time for bladder repair was significantly longer in ArtiSential group than robotic and straight-shaped groups (17.9 min vs. 5.5 min, p=0.002; 17.9 min vs. 9.3 min, p=0.026). There were no significant differences among groups in terms of blood loss or intraoperative complications. ArtiSential device was less useable for renorrhaphy (p=0.009) and bladder repair (p=0.002) compared to the robotic system. ArtiSential group was less accurate than robotic group in terms of tumor resection, renorrhaphy, and bladder repair. During ureter dissection, bladder cuff excision, and bladder repair, the surgeon experienced greater wrist discomfort but lesser back discomfort in ArtiSential group than robotic group. CONCLUSIONS: For most steps, ArtiSential performed as well as robotic and straight-shaped instruments. The development of specialized surgical techniques for ArtiSential will maximize the advantages of these instruments.

Therapeutic Effect of Three-Dimensional Cultured Adipose-Derived Stem Cell-Conditioned Medium in Renal Ischemia-Reperfusion Injury.

Background and Objectives: We evaluated the effect of adipose-derived stem cell-derived conditioned medium (ADSC-CM) on the renal function of rats with renal ischemia-reperfusion injury (IRI)-induced acute kidney injury. Methods and Results: Forty male Sprague-Dawley rats were randomly divided into four groups: sham, nephrectomy control, IRI control, ADSC-CM. The ADSC-CM was prepared using the three-dimensional spheroid culture system and injected into renal parenchyme. The renal function of the rats was evaluated 28 days before and 1, 2, 3, 4, 7, and 14 days after surgical procedures. The rats were sacrificed 14 days after surgical procedures, and kidney tissues were collected for histological examination. The renal parenchymal injection of ADSC-CM significantly reduced the serum blood urea nitrogen and creatinine levels compared with the IRI control group on days 1, 2, 3, and 4 after IRI. The renal parenchymal injection of ADSC-CM significantly increased the level of creatinine clearance compared with the IRI control group 1 day after IRI. Collagen content was significantly lower in the ADSC-CM group than in the IRI control group in the cortex and medulla. Apoptosis was significantly decreased, and proliferation was significantly increased in the ADSC-CM group compared to the IRI control group in the cortex and medulla. The expressions of anti-oxidative makers were higher in the ADSC-CM group than in the IRI control group in the cortex and medulla. Conclusions: The renal function was effectively rescued through the renal parenchymal injection of ADSC-CM prepared using a three-dimensional spheroid culture system.

Electroceutical approach ameliorates intracellular PMP22 aggregation and promotes pro-myelinating pathways in a CMT1A in vitro model.

Charcot-Marie-Tooth disease subtype 1A (CMT1A) is one of the most prevalent demyelinating peripheral neuropathies worldwide, caused by duplication of the peripheral myelin protein 22 (PMP22) gene, which is expressed primarily in Schwann cells (SCs). PMP22 overexpression in SCs leads to intracellular aggregation of the protein, which eventually results in demyelination. Unfortunately, previous biochemical approaches have not resulted in an approved treatment for CMT1A disease, compelling the pursuit for a biophysical approach such as electrical stimulation (ES). However, the effects of ES on CMT1A SCs have remained unexplored. In this study, we established PMP22-overexpressed Schwannoma cells as a CMT1A in vitro model, and investigated the biomolecular changes upon applying ES via a custom-made high-throughput ES platform, screening for the condition that delivers optimal therapeutic effects. While PMP22-overexpressed Schwannoma exhibited intracellular PMP22 aggregation, ES at 20 Hz for 1 h improved this phenomenon, bringing PMP22 distribution closer to healthy condition. ES at this condition also enhanced the expression of the genes encoding myelin basic protein (MBP) and myelin-associated glycoprotein (MAG), which are essential for assembling myelin sheath. Furthermore, ES altered the gene expression for myelination-regulating transcription factors Krox-20, Oct-6, c-Jun and Sox10, inducing pro-myelinating effects in PMP22-overexpressed Schwannoma. While electroceuticals has previously been applied in the peripheral nervous system towards acquired peripheral neuropathies such as pain and nerve injury, this study demonstrates its effectiveness towards ameliorating biomolecular abnormalities in an in vitro model of CMT1A, an inherited peripheral neuropathy. These findings will facilitate the clinical translation of an electroceutical treatment for CMT1A.

Efficacy and Safety of Human Bone Marrow-Derived Mesenchymal Stem Cells according to Injection Route and Dose in a Chronic Kidney Disease Rat Model.

Background and Objectives: We compared the efficacy and safety of human bone marrow-derived mesenchymal stem cells (hBMSC), delivered at different doses and via different injection routes in an animal model of chronic kidney disease. Methods and Results: A total of ninety 12-week-old rats underwent 5/6 nephrectomy and randomized among nine groups: sham, renal artery control (RA-C), tail vein control (TV-C), renal artery low dose (RA-LD) (0.5×106 cells), renal artery moderate dose (RA-MD) (1.0×106 cells), renal artery high dose (RA-HD) (2.0×106 cells), tail vein low dose (TV-LD) (0.5×106 cells), tail vein moderate dose (TV-MD) (1.0×106 cells), and tail vein high dose (TV-HD) (2.0×106 cells). Renal function and mortality of rats were evaluated after hBMSC injection. Serum blood urea nitrogen was significantly lower in the TV-HD group at 2 weeks (p<0.01), 16 weeks (p<0.05), and 24 weeks (p<0.01) than in the TV-C group, as determined by one-way ANOVA. Serum creatinine was significantly lower in the TV-HD group at 24 weeks (p<0.05). At 8 weeks, creatinine clearance was significantly higher in the TV-MD and TV-HD groups (p<0.01, p<0.05) than in the TV-C group. In the safety evaluation, we observed no significant difference among the groups. Conclusions: Our findings confirm the efficacy and safety of high dose (2×106 cells) injection of hBMSC via the tail vein.

Thermogelling hydrogel charge and lower critical solution temperature influence cellular infiltration and tissue integration in an ex vivo cartilage explant model.

Thermogelling hydrogels based on poly(N-isopropyl acrylamide) (p[NiPAAm]) and crosslinked with a peptide-bearing macromer poly(glycolic acid)-poly(ethylene glycol)-poly(glycolic acid)-di(but-2-yne-1,4-dithiol) (PdBT) were fabricated to assess the role of hydrogel charge and lower critical solution temperature (LCST) over time in influencing cellular infiltration and tissue integration in an ex vivo cartilage explant model over 21 days. The p(NiPAAm)-based thermogelling polymer was synthesized to possess 0, 5, and 10 mol% dimethyl-γ-butyrolactone acrylate (DBA) to raise the LCST over time as the lactone rings hydrolyzed. Further, three peptides were designed to impart charge into the hydrogels via conjugation to the PdBT crosslinker. The positively, neutrally, and negatively charged peptides K4 (+), zwitterionic K2E2 (0), and E4 (-), respectively, were conjugated to the modular PdBT crosslinker and the hydrogels were evaluated for their thermogelation behavior in vitro before injection into the cartilage explant models. Samples were collected at days 0 and 21, and tissue integration and cellular infiltration were assessed via mechanical pushout testing and histology. Negatively charged hydrogels whose LCST changed over time (10 mol% DBA) were demonstrated to promote the greatest tissue integration when compared to the positive and neutral gels of the same thermogelling polymer formulation due to increased transport and diffusion across the hydrogel-tissue interface. Indeed, the negatively charged thermogelling polymer groups containing 5 and 10 mol% DBA demonstrated cellular infiltration and cartilage-like matrix deposition via histology. This study demonstrates the important role that material physicochemical properties play in dictating cell and tissue behavior and can inform future cartilage tissue engineering strategies.

Farnesol prevents aging-related muscle weakness in mice through enhanced farnesylation of Parkin-interacting substrate.

Peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) is a master regulator of mitochondrial biogenesis. Reduced PGC-1α abundance is linked to skeletal muscle weakness in aging or pathological conditions, such as neurodegenerative diseases and diabetes; thus, elevating PGC-1α abundance might be a promising strategy to treat muscle aging. Here, we performed high-throughput screening and identified a natural compound, farnesol, as a potent inducer of PGC-1α. Farnesol administration enhanced oxidative muscle capacity and muscle strength, leading to metabolic rejuvenation in aged mice. Moreover, farnesol treatment accelerated the recovery of muscle injury associated with enhanced muscle stem cell function. The protein expression of Parkin-interacting substrate (PARIS/Zfp746), a transcriptional repressor of PGC-1α, was elevated in aged muscles, likely contributing to PGC-1α reduction. The beneficial effect of farnesol on aged muscle was mediated through enhanced PARIS farnesylation, thereby relieving PARIS-mediated PGC-1α suppression. Furthermore, short-term exercise increased PARIS farnesylation in the muscles of young and aged mice, whereas long-term exercise decreased PARIS expression in the muscles of aged mice, leading to the elevation of PGC-1α. Collectively, the current study demonstrated that the PARIS-PGC-1α pathway is linked to muscle aging and that farnesol treatment can restore muscle functionality in aged mice through increased farnesylation of PARIS.

Advantages of Adult Mouse Dorsal Root Ganglia Explant Culture in Investigating Myelination in an Inherited Neuropathic Mice Model.

A co-culture of neurons and Schwann cells has frequently been used to investigate myelin sheath formation. However, this approach is restricted to myelin-related diseases of the peripheral nervous system. This study introduces and compares an ex vivo model of adult-mouse-derived dorsal root ganglia (DRG) explant, with an in vitro co-culture of dissociated neurons from mouse embryo DRG and Schwann cells from a mouse sciatic nerve. The 2D co-culture has disadvantages of different mouse isolation for neurons and Schwann cells, animal number, culture duration, and the identification of disease model. However, 3D DRG explant neurons and myelination cells in Matrigel-coated culture are obtained from the same mouse, the culture period is shorter than that of 2D co-culture, and fewer animals are needed. In addition, it has simpler and shorter experimental steps than 2D co-culture. This culture system may prove advantageous in studies of biological functions and pathophysiological mechanisms of disease models, since it can reflect disease characteristics as traditional co-culture does. Therefore, it is suggested that a DRG explant culture is a scientifically, ethically, and economically more practical option than a co-culture system for studying myelin dynamics, myelin sheath formation, and demyelinating disease.

Therapeutic Effect of Human Mesenchymal Stem Cell-Conditioned Medium on Erectile Dysfunction.

PURPOSE: Owing to the safety and cost effectiveness of conditioned medium (CM), its therapeutic effects have attracted significant attention from many researchers. To date, numerous studies have been conducted on CM; however, little has been done with regard to erectile dysfunction (ED). In this research, the potential of human mesenchymal stem cell-derived CM (MSC-CM) for the treatment of ED was investigated. MATERIALS AND METHODS: A high concentration of MSC-CM was prepared through 3D spheroid culturing with bone marrow-derived MSCs and cut-off filtering. The composition of CM was analyzed using biochemical assays, and the effect of the preparation process on the quality of CM was investigated. The therapeutic effects of MSC-CM were evaluated through animal studies using a cavernous nerve (CN) injury rat model. RESULTS: 3D spheroid culturing afforded a 278-fold increase in the total protein content of CM, as compared to that from 2D cultures; the protein concentration increased by 19 times on increasing the centrifugation time for cut-off filtering. Biochemical assays indicated that the CM contains various types of angiogenic, neurotrophic, and anti-inflammatory factors. Histological assay results showed that MSC-CM has angio- and neuro-trophic effect in a CN injury rat model in vivo, and these therapeutic effects appear in a dose-dependent manner. CONCLUSIONS: The experimental results confirmed the therapeutic effect of MSC-CM in healing damaged cavernosal tissue and restoring erectile function. These results successfully demonstrated that MSC-CM has significant potential for the treatment of ED.

A dual-gelling poly(N-isopropylacrylamide)-based ink and thermoreversible poloxamer support bath for high-resolution bioprinting.

Extrusion bioprinting is a popular method for fabricating tissue engineering scaffolds because of its potential to rapidly produce complex, bioactive or cell-laden scaffolds. However, due to the relatively high viscosity required to maintain shape fidelity during printing, many extrusion-based inks lack the ability to achieve precise structures at scales lower than hundreds of micrometers. In this work, we present a novel poly(N-isopropylacrylamide) (PNIPAAm)-based ink and poloxamer support bath system that produces precise, multi-layered structures on the tens of micrometers scale. The support bath maintains the structure of the ink in a hydrated, heated environment ideal for cell culture, while the ink undergoes rapid thermogelation followed by a spontaneous covalent crosslinking reaction. Through the combination of the PNIPAAm-based ink and poloxamer bath, this system was able to produce hydrogel scaffolds with uniform fibers possessing diameters tunable from 80 to 200 µm. A framework of relationships between several important printing factors involved in maintaining support and thermogelation was also elucidated. As a whole, this work demonstrates the ability to produce precise, acellular and cell-laden PNIPAAm-based scaffolds at high-resolution and contributes to the growing body of research surrounding the printability of extrusion-based bioinks with support baths.

An electroceutical approach enhances myelination via upregulation of lipid biosynthesis in the dorsal root ganglion.

As the myelin sheath is crucial for neuronal saltatory conduction, loss of myelin in the peripheral nervous system (PNS) leads to demyelinating neuropathies causing muscular atrophy, numbness, foot deformities and paralysis. Unfortunately, few interventions are available for such neuropathies, because previous pharmaceuticals have shown severe side effects and failed in clinical trials. Therefore, exploring new strategies to enhance PNS myelination is critical to provide solution for such intractable diseases. This study aimed to investigate the effectiveness of electrical stimulation (ES) to enhance myelination in the mouse dorsal root ganglion (DRG)-anex vivomodel of the PNS. Mouse embryonic DRGs were extracted at E13 and seeded onto Matrigel-coated surfaces. After sufficient growth and differentiation, screening was carried out by applying ES in the 1-100 Hz range at the beginning of the myelination process. DRG myelination was evaluated via immunostaining at the intermediate (19 daysin vitro(DIV)) and mature (30 DIV) stages. Further biochemical analyses were carried out by utilizing ribonucleic acid sequencing, quantitative polymerase chain reaction and biochemical assays at both intermediate and mature myelination stages. Imaging of DRG myelin lipids was carried out via time-of-flight secondary ion mass spectrometry (ToF-SIMS). With screening ES conditions, optimal condition was identified at 20 Hz, which enhanced the percentage of myelinated neurons and average myelin length not only at intermediate (129% and 61%) but also at mature (72% and 17%) myelination stages. Further biochemical analyses elucidated that ES promoted lipid biosynthesis in the DRG. ToF-SIMS imaging showed higher abundance of the structural lipids, cholesterol and sphingomyelin, in the myelin membrane. Therefore, promotion of lipid biosynthesis and higher abundance of myelin lipids led to ES-mediated myelination enhancement. Given that myelin lipid deficiency is culpable for most demyelinating PNS neuropathies, the results might pave a new way to treat such diseases via electroceuticals.

Comparison of Stromal Vascular Fraction and Adipose-Derived Stem Cells for Protection of Renal Function in a Rodent Model of Ischemic Acute Kidney Injury.

Aims: Few studies have compared the use of different cell types derived from adipose tissue or the optimal route for efficient and safe cell delivery in ischemic acute kidney injury (AKI). We compared the abilities of stromal vascular fraction (SVF) and adipose-derived stem cells (ADSC), injected via three different routes, to protect renal function in a rodent model of ischemic AKI. Methods: Ninety male Sprague-Dawley rats were randomly divided into 9 groups: sham, nephrectomy control, AKI control, transaortic renal arterial SVF injection, renal parenchymal SVF injection, tail venous SVF injection, transaortic renal arterial ADSC injection, renal parenchymal ADSC injection, and tail venous ADSC injection groups. Their renal function was assessed 4 days before and 1, 2, 3, 4, 7, and 14 days after surgical procedures to induce ischemic AKI. The histomorphometric studies were performed 14 days after surgical procedures. Results: Renal parenchymal injection of SVF notably reduced the level of serum blood urea nitrogen and creatinine elevation compared to the AKI control group. Renal parenchymal injection of SVF notably reduced the level of creatinine clearance decrease. In addition, collagen content was lower in the renal parenchymal SVF injection group, and fibrosis was reduced. Apoptosis was reduced in the renal parenchymal SVF injection group, and proliferation was increased. The expression levels of antioxidative markers such as glutathione reductase and peroxidase were higher in the renal parenchymal SVF injection group. Conclusions: Our findings suggest that renal function is protected from ischemic AKI through renal parenchymal injection of SVF, which has enhanced antifibrotic, antiapoptotic, and antioxidative effects.