Laser Speckle Contrast Imaging Guides Needling Treatment of Vascular Complications from Dermal Fillers.

BACKGROUND: Although laser Doppler imaging (LDI) accurately delineates a hypoperfused area to help target hyaluronidase treatment, laser speckle contrast imaging (LSCI) is more appropriate for assessing microvascular hemodynamics and has greater reproducibility than LDI. This study investigated the use of LSCI in the evaluation and treatment of six patients who developed vascular complications after facial dermal filler injections. METHODS: The areas of vascular occlusion were accurately defined in real time by LSCI and were more precise than visual inspections or photographic evidence for guiding needling and hyaluronidase treatment. RESULTS: All patients had achieved satisfactory outcomes as early as Day 2 of treatment and no procedure-related complications were reported after a median follow-up of 9.5 (7-37) days. CONCLUSION: LSCI accurately and noninvasively delineated vascular occlusions in real time among patients experiencing complications of facial dermal filler injections. Moreover, LSCI was more accurate than visual and photographic evaluations. Clinicians can use LSCI to reliably follow-up therapeutic outcomes after salvage interventions for vascular occlusions. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Efficacy and safety of pectoralis muscle flap combined rectus abdominis muscle sheath fasciocutaneous flap for reconstruction of sternal infection.

Few studies have assessed the efficacy and safety of reconstruction of sternal infection using a pectoralis muscle flap combined with a rectus abdominis muscle (RAM) sheath fasciocutaneous flap. We report here our experience with this procedure to reconstruct the sternal defect in patients (n = 46) with a deep sternal wound infection (DSWI) after cardiac surgery. After wound reconstruction, the proportion of prolonged mechanical ventilation use and intensive care unit (ICU) stay were 17.4% (n = 8) and 21.7% (n = 10), respectively. The 30-day all-cause mortality was 15.2%; recurrence rate was 17.4%; postoperative complications were 15.2%; and median hospital stay was 31 (0-157) days. Multivariate logistic regression analysis revealed that hypertension (ß = 21.32, 95%CI 4.955-37.68, P = .014), drainage-tube use (ß = 0.944, 95%CI 0.273-1.614, P = .008), and prolonged intensive care unit stay (ß = 53.65, 95%CI 31.353-75.938, P < .001) were significantly correlated with hospital stay. In conclusion, a procedure including surgical debridement, sternal reconstruction with bilateral PM and RAM sheath flap, long-term antibiotics, and adequate drainage is a beneficial technique in the reconstruction of deep sternal wound infection after cardiac surgery. Duration of drainage tube use may be as an index for a hospital stay or wound healing.

pH-driven continuous stem cell production with enhanced regenerative capacity from polyamide/chitosan surfaces.

Adipose-derived stem cells (ASCs) have raised significant interest for their potential therapeutic applications in regenerative medicine. However, ASCs usually suffer from decreased pluripotency and functional plasticity during in vitro expansion. Herein, this study sought to develop a continuous cell production system that can mass-produce ASCs with sustained regenerative capacity. The strategy was blending pH-responsive chitosan (CS) with polyamide-66 (PA) to generate combined surface properties with controllable cell growth/detachment ability to achieve a repeated cell production process. From the collected data, all the polymer blends were capable of completing a minimum of four consecutive production cycles, wherein the PA17CS blend (PA:CS = 1:7) outperformed with respect to the working effectiveness (average cell detachment ratio = 88%) and the cell viability. Compared to the trypsin-based method, ASCs harvested from PA17CS exhibited superior stemness characteristics along with SDF-1-mediated CXCR4 chemotactic response for stem cell homing. Moreover, injection of ASCs generated from PA17CS blend could more effectively induce neovascularization and protect skin flaps during an ischemic injury in a rat model.

Novel Application of Photo-Crosslinked Urocanic-Acid-Modified Chitosan in Corneal Wounds.

In the last few years, the use of tissue adhesives in corneal perforation has gained immense popularity in clinical practices. The present study aimed to devise a new application of urocanic-acid-modified chitosan (CS) with methylene blue (MB) as a photosensitizer for the development of a photo-crosslinked tissue adhesive. In particular, the curing time was controlled with the aid of a 650 nm red diode. Under the same irradiation condition, the mechanical properties were tuned using the photosensitizer at different concentrations. In vitro tests revealed that the gel was ductile and biocompatible. The application of the gel to a perforated cornea model stopped the leakage of aqueous humor, immediately after the gel was photo-crosslinked. The blue appearance of the gel provided high precision when applied to corneal wounds. Importantly, the crosslinked gel became transparent within 24 h, owing to the dissipation of MB from tears, and the gel spontaneously sloughed off without artificial removal. Altogether, the study reported the development of a novel photo-crosslinkable urocanic-acid-modified CS gel that exhibited significant potential to be utilized in the healing of corneal perforation.

Poly(allylguanidine)-Coated Surfaces Regulate TGF-ß in Glioblastoma Cells to Induce Apoptosis via NF-κB Pathway Activation.

Polycationic biomaterials are currently widely applied in neuronal cell cultures to promote cell adhesion and viability. However, polycations generally have cytotoxic properties that limit their application in the field of biomaterials. In this study, we examined the use of a novel polycation poly(allylguanidine) (PAG), which contains a guanidine group in the side chain and a structure similar to poly(allylamine hydrochloride) (PAH), an example of another commonly used polycation. Our findings showed that exposure to PAG induced apoptosis in glioblastoma (GBM) cells, while exposure to PAH induced necrosis. Compared to control groups, the PAG coating significantly limited the proliferation of GBM8901 in vitro and in vivo. Furthermore, GBM8901 cells exposed to the PAG coating exhibited increased levels of phospho-p65 and phosphor-IκB, implying that GBM8901 cells underwent apoptotic cell death via the NF-κB pathway by the regulation of TGF-ß. This result was further confirmed to be consistent with the experimental results from western blot protein analysis and apoptosis/necrosis assays. These findings indicate that the polycation PAG has the potential to not only suppress the proliferation of GBM8901 cancer cells but also improve the neural viability and promote the differentiation of neural stem/precursor cells into mature neurons. In conclusion, biomaterials such as PAG act as extremely potent options for applications in the treatment of pathological conditions such as brain cancer.

Laser Doppler Imaging for Treating Vascular Complications from Procedures Involving Dermal Fillers: Case Series and Literature Review.

Vascular occlusion is a rare but severe complication of dermal filler injections. Early treatment of this complication produces better outcomes. Current diagnostic methods for vascular occlusion in the skin are subjective and imprecise; these include capillary refill time, skin color, and reports of pain. This study aimed to assess the use of laser Doppler imaging (LDI) in the evaluation and treatment of vascular complications caused by dermal filler injections. This retrospective study used laser Doppler imaging (LDI) in 13 patients who developed vascular occlusion after facial dermal filler injections, with subsequent follow-up. The precise areas of perfusion observed on LDI were compared with the findings of clinical and photographic evaluation. The results showed that LDI accurately identified areas of vascular occlusion and improved treatment precision among these thirteen patients. The procedure was more precise than visual inspection or photographic evidence. Satisfactory outcomes were achieved for all patients, and no procedure-related complications were reported. Collectively, LDI provides fast, noninvasive, and accurate delineation of areas of vascular occlusion caused by complications of dermal filler injections and avoids several subjective shortcomings of visual and photographic evaluations. Thus, LDI effectively tracks treatment outcomes. However, large-scale studies are required to confirm the present findings.

Hyaluronic acid on the urokinase sustained release with a hydrogel system composed of poloxamer 407: HA/P407 hydrogel system for drug delivery.

Pleural empyema is an inflammatory condition characterized by accumulation of pus inside the pleural cavity, which is usually followed by bacterial pneumonia. During the disease process, the pro-inflammatory and pro-fibrotic cytokines in the purulent pleural effusion cause proliferation of fibroblasts and deposition of extracellular matrix, which lead to fibrin deposition and fibrothorax. Urokinase instillation therapy through a chest drainage tube is frequently used for fibrinolysis in patients with empyema. However, urokinase treatment requires multiple instillation (2-3 times per day, for 4-8 days) and easily flows out from the chest drainage tube due to its high water solubility. In this in vitro study, we developed a thermo-responsive hydrogel based on poloxamer 407 (P407) combined with hyaluronic acid (HA) for optimal loading and release of urokinase. Our results show that the addition of HA to poloxamer gels provides a significantly more compact microstructure, with smaller pore sizes (**p < 0.001). The differential scanning calorimetry (DSC) profile revealed no influence on the micellization intensity of poloxamer gel by HA. The 25% poloxamer-based gel was significantly superior to the 23% poloxamer-based gel, with slower gel erosion when comparing the 16th hour residual gel weight of both gels (*p < 0.05; **p < 0.001). The 25% poloxamer-HA gel also exhibited a superior urokinase release profile and longer release time. A Fourier-transform infrared spectroscopy (FT-IR) study of the P407/HA hydrogel showed no chemical interactions between P407 and HA in the hydrogel system. The thermoresponsive P407/HA hydrogel may have a promising potential in the loading and delivery of hydrophilic drugs. On top of that, in vitro toxicity test of this combination demonstrates a lower toxicity.