Antimony-Platinum Modulated Contact Enabling Majority Carrier Polarity Selection on a Monolayer Tungsten Diselenide Channel.

We develop a novel metal contact approach using an antimony (Sb)-platinum (Pt) bilayer to mitigate Fermi-level pinning in 2D transition metal dichalcogenide channels. This strategy allows for control over the transport polarity in monolayer WSe2 devices. By adjustment of the Sb interfacial layer thickness from 10 to 30 nm, the effective work function of the contact/WSe2 interface can be tuned from 4.42 eV (p-type) to 4.19 eV (n-type), enabling selectable n-/p-FET operation in enhancement mode. The shift in effective work function is linked to Sb-Se bond formation and an emerging n-doping effect. This work demonstrates high-performance n- and p-FETs with a single WSe2 channel through Sb-Pt contact modulation. After oxide encapsulation, the maximum current density at |VD| = 1 V reaches 170 µA/µm for p-FET and 165 µA/µm for n-FET. This approach shows promise for cost-effective CMOS transistor applications using a single channel material and metal contact scheme.

Fabrication of Luminescent Triple-Cross-Linked Gelatin/Alginate Hydrogels through Freezing-Drying-Swelling and Freezing-Thawing Processes.

Lanthanide-containing luminescent hydrogels have shown potential for sensing and imaging applications. Nonetheless, integrating lanthanide ions or complexes into the polymer matrix often results in the poor stability and mechanical strength of the hydrogels. This work presents an innovative approach to fabricating luminescent hydrogels with three dynamic cross-links: imine bond, boronate ester bond, and metal-ligand coordination. Europium(III) (Eu3+) ions are incorporated into a dual-cross-linked matrix composed of phenylboronic acid-polyethylenimine-modified gelatin (PPG) and alginate dialdehyde (ADA) through a combined treatment involving freeze-drying-swelling (FDS) and freeze-thawing (FT) processes. The FDS process facilitates the formation of additional europium-carboxylate cross-links within the polymeric network to enhance its luminescence and stability, while the FT process strengthens the network physically. The impact of the FDS-FT cycle number on the microstructures and properties of PPG/ADA-Eu3+ hydrogels is thoroughly investigated, and their potential for monitoring bacterial growth and detecting copper(II) ions is also demonstrated.

Split Anterolateral Thigh Flap: A New Classification of Anatomical Variants and a Surgical Planning Algorithm.

BACKGROUND: Split anterolateral thigh flap is a versatile reconstruction option, yet long underestimated as no practical perforator classification and no optimal strategy were present. Harvesting "capillary nonsizable perforators" could potentially expand flap splits to those with no existing multiple sizable perforators. Concerns over defect characteristics, recipient vessels, pedicle length, and split timing should all be weighted equally in designing the suitable flap. Refinement is thus required to enable precise reconstructions. METHODS: All patients undergoing anterolateral thigh flap harvests between 2014 and 2021 performed by a single surgeon were included. The perforator patterns of sizable pedicle, course, origin, and further successful flap-split methods were documented. Surgical outcome of flap survival was analyzed. RESULTS: Anatomical variants of 134 (48.4%) dual, 123 (44.4%) single, and 20 (7.2%) no sizable perforators were found in a total of 277 anterolateral thigh flaps. The overall flap survival rate was 97.5%. Flap split was performed in 82 flaps, including 29 single and 5 no sizable perforator cases previously considered "unsplittable," by utilizing a series of direct skin paddle split, capillary nonsizable perforators harvesting, and flow-through anastomosis technique. Comparable flap survivals were found between split and nonsplit flaps as well as between split segments supplied by sizable and capillary nonsizable perforators. Primary closure was achieved in 98.9% of the thigh donor sites. CONCLUSION: A new classification of the common anterolateral thigh flap anatomical variants was proposed and a comprehensive algorithm of split flap strategy was developed along with the innovative "fabricate" concept.

A Comparison Study of Outcomes and Complications Between Marginal Mandibulectomy With or Without Additional Mandibulotomy in Tongue Cancers.

BACKGROUND: Marginal mandibulectomy with or without additional mandibulotomy could represent the alternatives to avoid segmental mandibulectomy in carefully selected tongue cancers. AIM AND OBJECTIVES: This study investigated a subgroup of tongue cancers with suspected involvement to the alveolar bone because of the shallow and deformed mouth floor. We aimed to compare the functional outcomes, postoperative complications, and disease control efficacy between the 2 different marginal mandibulectomy approaches, with or without additional mandibulotomy. MATERIALS AND METHODS: A retrospective study of 29 marginal mandibulectomies and 26 combined mandibulotomies for tongue cancer wide excisions and flap reconstruction at Chang Gung Memorial Hospital Linkou Branch during 2014 to 2019 was performed. RESULTS: The combined mandibulotomy group had more advanced T-status ( P < 0.001) and greater tumor diameters ( P < 0.001) but not increased preexisting trismus, bone invasions, or positive margins. The additional mandibulotomy increased flap necrosis ( P = 0.044), late infections ( P = 0.004), and tongue movement limitations ( P = 0.044) but not osteoradionecrosis. Osteoradionecrosis was unrelated to the resected mandibular length or the mandibulotomy sites. Feeding tube dependence was greater in the combined group at discharge ( P = 0.014), but no long-term differences were noted. Kaplan-Meier overall survival ( P = 0.052) and disease-free survival ( P = 0.670) were both comparable between the 2 groups. CONCLUSIONS: The combined procedure of mandibulotomy and marginal mandibulectomy in large tongue cancers without bone invasions is associated with increased soft tissue-related complications but not bone-related complications. However, comparable disease control, survival, and long-term tube feeding outcomes were noted.

Systematic Screening for SARS-CoV-2 to Detect Asymptomatic Infections: An Epitome of Taiwan's Outbreak.

BACKGROUND: Increased studies have revealed that asymptomatic carriers substantially impact the epidemic and that asymptomatic transmission is very common. Therefore, the asymptomatic transmission threat to the spread of the pandemic should not be neglected. METHODS: The local outbreak in Taiwan, especially in Taipei City, is unprecedented and paramount and has claimed hundreds of lives, tens of thousands of cases, and enormous economic costs. As care providers and gatekeepers of infectious diseases, Taipei City Hospital has to perform regular polymerase chain reaction (PCR) results of admitted patients and healthcare workers (HCWs) to achieve these goals. RESULTS: In this study, the results revealed a low positive rate of less than 1%, but the asymptomatic proportions could range from 42% to 46%, which bolsters that systematic screening was effective in controlling coronavirus disease-19 (COVID-19) of Novel Coronavirus or Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2) and might be an exemplar to other similar scenarios. Universal screening of admitted patients may be important and necessary, especially in asymptomatic patients. CONCLUSIONS: Regular screening for healthcare providers is also important during this pandemic, and it is recommended that admitted patients and healthcare providers undergo systemic PCR testing.

Increased risk of pulmonary and extrapulmonary tuberculosis infection in patients with polycystic kidney disease: a nationwide population-based study with propensity score-matching analysis.

BACKGROUND: Polycystic kidney disease (PKD) is a common renal disorder affecting approximately 1 in 1000 live births. Tuberculosis (TB) is an infectious disease worldwide. This study investigated the risk of TB infection in patients with PKD. METHODS: A nationwide population-based cohort study was performed using Taiwan's National Health Insurance Research Database. We used patients' hospitalization files for the entire analysis during 2000-2012. As per diagnosis, we divided patients into PKD and non-PKD cohorts and the major outcome was TB infection. RESULTS: A total of 13,540 participants with 6770 patients in each cohort were enrolled. The PKD cohort had a higher risk of TB infection than did the non-PKD cohort after adjusting for age, sex, and comorbidities (adjusted hazard ratio (aHR) = 1.91, 95% confidence interval [CI] = 1.51-2.43). When classifying by sites of pulmonary TB (PTB) and extrapulmonary TB (EPTB), the PKD cohort demonstrated a significantly higher risk of EPTB (aHR = 2.44, 95% CI = 1.46-4.08) as well as a risk of PTB (aHR = 1.69, 95% CI = 1.29-2.22). When stratified by the presence or absence of a comorbidity, high TB infection risk was noted in the PKD patients without any comorbidity (HR = 2.69, 95% CI = 1.69-4.30). CONCLUSIONS: Taken together, our findings suggest that PKD is associated with a 1.91-fold increased risk of TB infection. Medical professionls should maintain a high index of suspicion in daily practice for patients with PKD, particularly those with EPTB infection.

Rapid Biocidal Activity of N-Halamine-Functionalized Polydopamine and Polyethylene Imine Coatings.

Microorganisms easily adhere to the surface of substrates and further form biofilms, which present problems in various fields. Therefore, the development of surfaces with antimicrobial adhesion or viability is a promising approach. In this study, we were committed to develop a rapid sterilizing coating. First, polyester fibers were immersed into a mixing solution of dopamine (PDA) and polyethyleneimine (PEI) for forming the co-deposition of PDA and PEI coatings. After this, the co-deposition of PDA and PEI coatings was immersed in a solution of household bleach for chlorination. We found that the nitrogens of PDA and PEI could be chlorinated repeatedly and that the oxidative chlorine content increased with the increasing PEI concentration upon co-deposition. Next, the efficacy of the co-deposition of chlorinated PDA and PEI coatings in eliminating Staphylococcus aureus and Escherichia coli was investigated. We found that the antibacterial ability of the coatings increased with increasing PEI content. In addition, the chlorinated co-deposition coatings had significantly improved antibacterial properties compared to the unchlorinated ones. The chlorinated co-deposition coatings inactivated >99.99% of S. aureus and >99.9% of E. coli after contact of less than 10 min. Therefore, chlorination of a PDA/PEI co-deposition surface is a feasible method for use in antibacterial coatings.

Changes in pediatric seizure-related emergency department attendances during COVID-19 - A territory-wide observational study.

A territory-wide retrospective observational study was conducted in Hong Kong between January 23 to April 22, 2020 to demonstrate changes in pediatric seizure-related accident and emergency department (A&E) visits during the COVID-19 pandemic. Parallel periods from 2015 to 2019 were used as control. All-cause A&E attendances in all paediatric age groups decreased significantly during the study period. Seizure-related attendances decreased across all pediatric age-groups in 2020 (RR 0.379, 95% CI 0.245-0.588), with a disproportionately large decrease in the 0-6 years age group (RR 0.303, 95% CI 0.174-0.526) compared with the 7-18 years age group (RR 0.534, 95% CI 0.393-0.719). Decrease in RTI-related A&E attendances was also more drastic in the 0-6 age group. The two time trends are congruent in the 0-6 years but not the 7-18 years age group. Such a trend is suggestive of the usefulness of infection control measures in seizure prevention, especially amongst young children.

The Benefits of the Supercharged Ileocolic Flap in Patients Who Underwent Total Esophagectomy and Gastrectomy.

BACKGROUND: Patients who undergo total esophagectomy and gastrectomy present a challenging scenario for reconstructive surgeons. Several techniques have been described. However, the best choice is still a matter of debate. We aim to report our experience with the supercharged ileocolic flap, then to compare the long-term functional outcomes in cancer and caustic injury patients. We investigate the safest route of transposition and demonstrate the importance of supercharging the flap. Last, we perform a literature review to compare our results with the ones reported in the literature. METHODS: A total of 36 patients underwent the supercharged ileocolic flap procedure. The details reviewed included the type of defect, flap characteristic, route of transposition, complications, patient survival, and swallowing evaluation. Survival and long-term function preservation were considered as the main outcomes. A secondary end-point was the identification of the safest route of transposition. We extracted the pertinent literature on supercharged bowel flaps from 1995 to July 2020 RESULTS: All flaps survived; only two flaps were partially lost. Thirty-three percent of the cohort experienced postoperative complications; the most common was leakage of the cervical anastomosis (17%), followed by neck wound infection (8%). The 5-year dysphagia-free survival rate was 87% in corrosive injury patients and 78% in cancer patients. The mean time to be free from dysphagia after surgery was 25.12 ± 4.55 months for corrosive patients and 39.56 ± 9.45 months for cancer patients (p = 0.118). The safest route of transposition was retrosternal extra-mediastinal. From the literature review, the data from 11 studies were extracted. CONCLUSION: The supercharged ileocolic flap is a robust option for total esophageal replacement when the stomach is not available and the retrosternal route is the safest for transposition. The functional outcomes are excellent, with acceptable morbidity and a good life expectancy, either in cancer and noncancer patients. Supercharging the flap is recommended.

Nerve growth factor induced farnesoid X receptor upregulation modulates autophagy flux and protects hepatocytes in cholestatic livers.

Upregulation of nerve growth factor (NGF) in parenchymal hepatocytes has been shown to exert hepatoprotective function during cholestatic liver injury. However, the modulatory role of NGF in regulation of liver autophagy remains unclear. This study aimed to scrutinize the regulatory role of NGF in hepatic expression of farnesoid X receptor (FXR), a bile acid (BA)-activated nuclear receptor, and to determine its cytoprotective effect on BA-induced autophagy and cytotoxicity. Livers of human hepatolithiasis and bile duct ligation (BDL)-induced mouse cholestasis were used for histopathological and molecular detection. The regulatory roles of NGF in autophagy flux and FXR expression, as well as its hepatoprotection against BA cytotoxicity were examined in cultured hepatocytes. FXR downregulation in human hepatolithiasis livers showed positive correlation with hepatic NGF levels. NGF administration upregulated hepatic FXR levels, while neutralization of NGF decreased FXR expression in BDL-induced cholestatic mouse livers. In vitro studies demonstrated that NGF upregulated FXR expression, increased cellular LC3 levels, and exerted hepatoprotective effect in cultured primary rat hepatocytes. Conversely, autophagy inhibition abrogated NGF-driven cytoprotection under BA exposure, suggesting involvement of NGF-modulated auophagy flux. Although FXR agonistic GW4064 stimulation did not affect auophagic LC3 levels, FXR activity inhibition significantly potentiated BA-induced cytotoxicity and increased cellular p62/SQSTM1 and Rab7 protein in SK-Hep1 hepatocytes. Moreover, FXR gene silencing abolished the protective effect of NGF under BA exposure. These findings support that NGF modulates autophagy flux via FXR upregulation and protects hepatocytes against BA-induced cytotoxicity. NGF/FXR axis is a novel therapeutic target for treatment of cholestatic liver diseases.

Effect of ventilation improvement during a tuberculosis outbreak in underventilated university buildings.

The role of ventilation in preventing tuberculosis (TB) transmission has been widely proposed in infection control guidance. However, conclusive evidence is lacking. Modeling suggested the threshold of ventilation rate to reduce effective reproductive ratio (ratio between new secondary infectious cases and source cases) of TB to below 1 is corresponding to a carbon dioxide (CO2 ) level of 1000 parts per million (ppm). Here, we measured the effect of improving ventilation rate on a TB outbreak involving 27 TB cases and 1665 contacts in underventilated university buildings. Ventilation engineering decreased the maximum CO2 levels from 3204 ± 50 ppm to 591-603 ppm. Thereafter, the secondary attack rate of new contacts in university dropped to zero (mean follow-up duration: 5.9 years). Exposure to source TB cases under CO2 >1000 ppm indoor environment was a significant risk factor for contacts to become new infectious TB cases (P < .001). After adjusting for effects of contact investigation and latent TB infection treatment, improving ventilation rate to levels with CO2 <1000 ppm was independently associated with a 97% decrease (95% CI: 50%-99.9%) in the incidence of TB among contacts. These results show that maintaining adequate indoor ventilation could be a highly effective strategy for controlling TB outbreaks.

Facile Generation of Thermally Activated Delayed Fluorescence and Fabrication of Highly Efficient Non-Doped OLEDs Based on Triazine Derivatives.

A series of donor-acceptor-donor triazine-based molecules with thermally activated delayed fluorescence (TADF) properties were synthesized to obtain highly efficient blue-emitting OLEDs with non-doped emitting layers (EMLs). The targeted molecules use a triazine core as the electron acceptor, and a benzene ring as the conjugated linker with different electron donors to alternate the energy level of the HOMO to further tune the emission color. The introduction of long alkyl chains on the triazine core inhibits the unwanted intermolecular D-D/A-A-type π-π interactions, resulting in the intermolecular D-A charge transfer. The weak aggregation-caused quenching (ACQ) effect caused by the suppressed intermolecular D-D/A-A-type π-π interaction further enhances the emission. The crowded molecular structure allows the electron donor and acceptor to be nearly orthogonal, thereby reducing the energy gap between triplet and singlet excited states (ΔEST ). As a result, blue-emitting devices with TH-2DMAC and TH-2DPAC non-doped EMLs showed satisfactory efficiencies of 12.8 % and 15.8 %, respectively, which is one of the highest external quantum efficiency (EQEs) reported for blue TADF emitters (λpeak <475 nm), demonstrating that our tailored molecular designs are promising strategies to endow OLEDs with excellent electroluminescent performances.

Transcriptome analysis reveals a positive role for nerve growth factor in retinol metabolism in primary rat hepatocytes.

Up-regulation of nerve growth factor (NGF) in parenchymal hepatocytes with cholestatic injury has been previously demonstrated to exert hepatoprotective effects in an autocrine manner; however, the overall impact of NGF up-regulation remains elusive. This study aimed to profile the effects of exogenous NGF on cultured primary rat hepatocytes using transcriptome analysis. Total RNA was isolated from hepatocytes with and without 24 h of NGF exposure, and subjected to RNA enrichment by PCR and RNA sequencing procedures. Comparison of transcriptome profiles between control and NGF-stimulated hepatocytes demonstrated that NGF significantly up-regulated 10 genes and down-regulated 23 genes in hepatocytes. Subsequent KEGG pathway enrichment analysis indicated that NGF significantly affected the retinol metabolism pathway via increased retinol dehydrogenase 16 (RDH16) expression. In a mouse model of bile duct ligation-induced cholestatic liver injury, NGF supplementation significantly enhanced RDH16 expression, whereas administration of anti-NGF neutralizing antibodies prominently decreased RDH16 expression in cholestatic livers, supporting the positive role of NGF in the regulation of RDH16 in diseased livers. In vitro study further demonstrated that NGF triggered de novo synthesis of RDH16 in primary rat hepatocytes, mainly through an NF-κB signaling pathway. In conclusion, this study demonstrates the up-regulation of RDH16 by NGF in cultured rat hepatocytes and mouse cholestatic livers, and provides novel insights on the mechanistic role of NGF in the retinol metabolism of livers.

Methemoglobin Formation and Characterization of Hemoglobin Adducts of Carcinogenic Aromatic Amines and Heterocyclic Aromatic Amines.

Arylamines (AAs) and heterocyclic aromatic amines (HAAs) are structurally related carcinogens formed during the combustion of tobacco or cooking of meat. They undergo cytochrome P450 mediated N-hydroxylation to form metabolites which bind to DNA and lead to mutations. The N-hydroxylated metabolites of many AAs also can undergo a co-oxidation reaction with oxy-hemolgobin (HbO2) to form methemoglobin (met-Hb) and the arylnitroso intermediates, which react with the ß-Cys(93) chain of Hb to form Hb-arylsulfinamide adducts. The biochemistry of arylamine metabolism has been exploited to biomonitor certain AAs through their Hb arylsulfinamide adducts in humans. We examined the reactivity of HbO2 with the N-hydroxylated metabolites of 4-aminobiphenyl (ABP, HONH-ABP), aniline (ANL, HONH-ANL), and the HAAs 2-amino-9H-pyrido[2,3-b]indole (AαC, HONH-AαC), 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP, HONH-PhIP), and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx, HONH-MeIQx). HONH-ABP, HO-ANL, and HONH-AαC induced methemoglobinemia and formed Hb sulfinamide adducts. However, HONH-MeIQx and HONH-PhIP did not react with the oxy-heme complex, and met-Hb formation and chemical modification of the ß-Cys(93) residue were negligible. Molecular modeling studies showed that the distances between the H-ON-AA or H-ON-HAA substrates and the oxy-heme complex of HbO2 were too far away to induce methemoglobinemia. Different conformational changes in flexible helical and loop regions around the heme pocket induced by the H-ON-AA or H-ON-HAAs may explain the different proclivities of these chemicals to induce methemoglobinemia. Hb-Cys(93ß) sulfinamide and sulfonamide adducts of ABP, ANL, and AαC were identified, by Orbitrap MS, following the proteolysis of Hb with trypsin, Glu-C, or Lys-C. Hb sulfinamide and sulfonamide adducts of ABP were identified in the blood of mice exposed to ABP, by Orbitrap MS. This is the first report of the identification of intact Hb sulfinamide adducts of carcinogenic AAs in vivo. The high reactivity of HONH-AαC with HbO2 suggests that the Hb sulfinamide adduct of AαC may be a promising biomarker of exposure to this HAA in humans.

Therapeutic evaluation of HIV transduction basic domain-conjugated superoxide dismutase solution on suppressive effects of the formation of peroxynitrite and expression of COX-2 in murine skin.

BACKGROUND: Homeostasis of reactive oxygen species (ROS) in the skin is regulated by antioxidant defenses. The inflammatory states of skin diseases which range from acute rashes to chronic conditions are related to the level of ROS. The involvement of superoxide dismutase (SOD) in restoring the antioxidant capacity can then neutralize the inflammatory response. RESULTS: We found that denatured Tat-SOD formulated in an aqueous medium could be delivered into mouse skin and the penetration signals of Tat-SOD were detected in the epidermis and dermis. According to immunohistochemical staining, Tat-SOD successfully suppressed inflammation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA), the expression of sodium nitroferricyanide (SNP)-induced cyclooxygenase-2 (COX-2), and the production of nitrotyrosine proteins. In nerve growth factor (NGF) induced differentiated PC12 pheochromocytoma cells, we demonstrated that the denatured Tat-SOD regained its antioxidant activity and effectively protected PC12 cells from DNA fragmentation induced by paraquat. Using a luciferase reporter assay, the data was shown Tat-SOD protected PC12 cells from ROS damage, through suppression of COX-2 or nuclear factor-κB (NF-κB) activity occurred at the transcriptional level. CONCLUSION: We showed that Tat-SOD inhibited SNP-induced COX-2 expression similarly to celecoxib and prevented the formation of peroxynitrite as 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide. The results suggest that denatured Tat-SOD solution may perform potential protein therapy for patients suffering from disorders related to ROS.

Single versus Double Plate Fixation in Condylar Neck Fractures: Clinical Results and Biomechanics Simulation.

The open reduction of mandibular condyle neck fractures is difficult due to the limited surgical field and complex facial nerve structures. The most effective fixation method for narrow fractured segments is debated as standard double four-hole plate fixation is often not feasible. This research compared bone stability and force resistance between single-long-plate and double-short-plate fixations using clinical outcomes, a Sawbones mandible model, and finite element analysis. In patients with condyle neck fractures, nine were fixed with single-long-plate and twelve with double-short-plate fixations, with no significant differences in malocclusion and facial palsy rates. In compression tests with a Sawbones model, displacements in the posterior part were similar in both fixation groups. In contrast, the anterior part had significantly higher displacements in the single-long-plate group. Finite element analysis showed higher displacements in both anterior and posterior parts in the single-plate group compared to the double-short-plate group. Maximum stresses were at the second screw hole in single-long-plate fixation and the turning point of the upper plate at the condyle neck in double-short-plate fixation. Double-short-plate fixations demonstrated better stability and force resistance than single-long-plate fixations.

A review of pharyngocutaneous fistula management in head and neck malignancies.

Pharyngocutaneous fistula is a serious complication after head and neck reconstruction and concurrent chemoradiotherapy, yet no consensus or practical protocols regarding the surgical timing and specific procedures could be found in the current literature. The authors aimed to review their clinical experience in surgical management and develop an algorithmic approach accordingly. A retrospective review of all hypopharyngeal cancer patients who developed pharyngocutaneous fistula during 2017 to 2021 at E-Da Hospital was conducted. Seventeen patients developed pharyngocutaneous fistula in all 321 pharyngeal cancer admissions during this period. Three patients received interventions at acute stage (≤2 weeks), with two direct repairs Three patients received interventions at acute stage (≤2 weeks), with two direct repairs and one regional flap coverage then negative pressure wound therapy. Nine received interventions at subacute stages (2 weeks to 3 months), with 4 resolved after debridement and direct repair yet another 4 underwent regional flap reconstruction and 1 free flap reconstruction. Five chronic fistula (>3 months) received secondary reconstructions utilizing a double-layered repair of local turn-over flaps for the internal mucosal opening and another flap harvest (four regional flaps and one free flap) to cover the outer skin defect. All patients after the palliative surgery achieved complete remission of fistula at follow follow-up. Different conservative and surgical approaches should be adopted according to the acute, subacute, and chronic stages of pharyngocutaneous fistula after palliative head and neck reconstructions.

Fabrication of triple-crosslinked gelatin/alginate hydrogels for controlled release applications.

Hydrogels have been demonstrated as smart drug carriers to recognize the tumor microenvironment for cancer treatment, where the dynamic crosslinks in the hydrogel network contribute to the stimuli-responsive features but also result in poor stability and weak mechanical property of the hydrogels. Here, phenylboronic acid-grafted polyethyleneimine (PBA-PEI)-modified gelatin (PPG) was synthesized to crosslink alginate dialdehyde (ADA) through imine bonds and boronate ester bonds, and then calcium ions (Ca2+) were added to introduce the third calcium-carboxylate crosslinking in the network to form the triple-crosslinked PPG/ADA-Ca2+ hydrogels. Given the three types of dynamic bonds in the network, PPG/ADA-Ca2+ hydrogels possessed a self-healing manner, stimuli-responsiveness, and better mechanical properties compared to single- or double-crosslinked hydrogels. The controlled release capability of PPG/ADA-Ca2+ hydrogels was also demonstrated, showing the encapsulated molecules can be rapidly released from the hydrogel network in the presence of hydrogen peroxide while the release rate can be slowed down at acidic pH. Furthermore, PPG/ADA-Ca2+ hydrogels presented selected cytotoxicity and drug delivery to cancer cells due to the regulated degradation by the cellular microenvironment. Taken together, PPG/ADA-Ca2+ hydrogels have been demonstrated as promising biomaterials with multiple desirable properties and dynamic features to perform controlled molecule release for biomedical applications.