Synthetic molecular motor activates drug delivery from polymersomes.

The design of stimuli-responsive systems in nanomedicine arises from the challenges associated with the unsolved needs of current molecular drug delivery. Here, we present a delivery system with high spatiotemporal control and tunable release profiles. The design is based on the combination of an hydrophobic synthetic molecular rotary motor and a PDMS-b-PMOXA diblock copolymer to create a responsive self-assembled system. The successful incorporation and selective activation by low-power visible light (λ = 430 nm, 6.9 mW) allowed to trigger the delivery of a fluorescent dye with high efficiencies (up to 75%). Moreover, we proved the ability to turn on and off the responsive behavior on demand over sequential cycles. Low concentrations of photoresponsive units (down to 1 mol% of molecular motor) are shown to effectively promote release. Our system was also tested under relevant physiological conditions using a lung cancer cell line and the encapsulation of an Food and Drug Administration (FDA)-approved drug. Similar levels of cell viability are observed compared to the free given drug showing the potential of our platform to deliver functional drugs on request with high efficiency. This work provides an important step for the application of synthetic molecular machines in the next generation of smart delivery systems.

IMMUNOREACT 7: Regular aspirin use is associated with immune surveillance activation in colorectal cancer.

BACKGROUND: Long-term daily use of aspirin reduces incidence and mortality due to colorectal cancer (CRC). This study aimed to analyze the effect of aspirin on the tumor microenvironment, systemic immunity, and on the healthy mucosa surrounding cancer. METHODS: Patients with a diagnosis of CRC operated on from 2015 to 2019 were retrospectively analyzed (METACCRE cohort). Expression of mRNA of immune surveillance-related genes (PD-L1, CD80, CD86, HLA I, and HLA II) in CRC primary cells treated with aspirin were extracted from Gene Expression Omnibus-deposited public database (GSE76583). The experiment was replicated in cell lines. The mucosal immune microenvironment of a subgroup of patients participating in the IMMUNOREACT1 (ClinicalTrials.gov NCT04915326) project was analyzed with immunohistochemistry and flow cytometry. RESULTS: In the METACCRE Cohort, 12% of 238 patients analyzed were aspirin users. Nodal metastasis was significantly less frequent (p = .008) and tumor-infiltrating lymphocyte infiltration was higher (p = .02) among aspirin users. In the CRC primary cells and selected cell lines, CD80 mRNA expression was increased following aspirin treatment (p = .001). In the healthy mucosa surrounding rectal cancer, the ratio of CD8/CD3 and epithelial cells expressing CD80 was higher in aspirin users (p = .027 and p = .034, respectively). CONCLUSIONS: These data suggested that regular aspirin use may have an active role in enhancing immunosurveillance against CRC.

Programmable Compartment Networks by Unraveling the Stress-Dependent Deformation of Polymer Vesicles.

Nanocontainers that can sense and respond to environmental stimuli like cells are desirable for next-generation delivery systems. However, it is still a grand challenge for synthetic nanocontainers to mimic or even surpass the shape adaption of cells, which may produce novel compartments for cargo loading. Here, this work reports the engineering of compartment network with a single polymer vesicle by unraveling osmotic stress-dependent deformation. Specifically, by manipulating the way in exerting the stress, sudden increase or gradual increase, polymer vesicles can either undergo deflation into the stomatocyte, a bowl-shaped vesicle enclosing a new compartment, or tubulation into the tubule of varied length. Such stress-dependent deformation inspired us to program the shape transformation of polymer vesicles, including tubulation, deflation, or first tubulation and then deflation. The coupled deformation successfully transforms the polymer vesicle into the stomatocyte with tubular arms and a network of two or three small stomatocytes connected by tubules. To the author's knowledge, these morphologies are still not accessed by synthetic nanocontainers. This work envisions that the network of stomatocytes may enable the loading of different catalysts to construct novel motile systems, and the well-defined morphology of vesicles helps to define the effect of morphology on cellar uptake.

Rivaroxaban vs placebo for extended antithrombotic prophylaxis after laparoscopic surgery for colorectal cancer.

The clinical benefit of extended prophylaxis for venous thromboembolism (VTE) after laparoscopic surgery for cancer is unclear. The efficacy and safety of direct oral anticoagulants for this indication are unexplored. PROphylaxis of venous thromboembolism after LAParoscopic Surgery for colorectal cancer Study II (PROLAPS II) was a randomized, double-blind, placebo-controlled, investigator-initiated, superiority study aimed at assessing the efficacy and safety of extended prophylaxis with rivaroxaban after laparoscopic surgery for colorectal cancer. Consecutive patients who had laparoscopic surgery for colorectal cancer were randomized to receive rivaroxaban (10 mg once daily) or a placebo to be started at 7 ± 2 days after surgery and given for the subsequent 3 weeks. All patients received antithrombotic prophylaxis with low-molecular-weight heparin from surgery to randomization. The primary study outcome was the composite of symptomatic objectively confirmed VTE, asymptomatic ultrasonography-detected deep vein thrombosis (DVT), or VTE-related death at 28 ± 2 days after surgery. The primary safety outcome was major bleeding. Patient recruitment was prematurely closed due to study drug expiry after the inclusion of 582 of the 646 planned patients. A primary study outcome event occurred in 11 of 282 patients in the placebo group compared with 3 of 287 in the rivaroxaban group (3.9 vs 1.0%; odds ratio, 0.26; 95% confidence interval [CI], 0.07-0.94; log-rank P = .032). Major bleeding occurred in none of the patients in the placebo group and 2 patients in the rivaroxaban group (incidence rate 0.7%; 95% CI, 0-1.0). Oral rivaroxaban was more effective than placebo for extended prevention of VTE after laparoscopic surgery for colorectal cancer without an increase in major bleeding. This trial was registered at www.clinicaltrials.gov as #NCT03055026.

IMMUNOREACT 6: weak immune surveillance characterizes early-onset rectal cancer.

BACKGROUND: Colon cancer in young patients is often associated with hereditary syndromes; however, in early-onset rectal cancer, mutations of these genes are rarely observed. The aim of this study was to analyse the features of the local immune microenvironment and the mutational pattern in early-onset rectal cancer. METHODS: Commonly mutated genes were analysed within a rectal cancer series from the University Hospital of Padova. Mutation frequency and immune gene expression in a cohort from The Cancer Genome Atlas ('TCGA') were compared and immune-cell infiltration levels in the healthy rectal mucosa adjacent to rectal cancers were evaluated in the IMMUNOlogical microenvironment in REctal AdenoCarcinoma Treatment 1 and 2 ('IMMUNOREACT') series. RESULTS: In the authors' series, the mutation frequency of BRAF, KRAS, and NRAS, as well as microsatellite instability frequency, were not different between early- and late-onset rectal cancer. In The Cancer Genome Atlas series, among the genes with the most considerable difference in mutation frequency between young and older patients, seven genes are involved in the immune response and CD69, CD3, and CD8ß expression was lower in early-onset rectal cancer. In the IMMUNOlogical microenvironment in REctal AdenoCarcinoma Treatment 1 and 2 series, young patients had a lower rate of CD4+ T cells, but higher T regulator infiltration in the rectal mucosa. CONCLUSION: Early-onset rectal cancer is rarely associated with common hereditary syndromes. The tumour microenvironment is characterized by a high frequency of mutations impairing the local immune surveillance mechanisms and low expression of immune editing-related genes. A constitutively low number of CD4 T cells associated with a high number of T regulators indicates an imbalance in the immune surveillance mechanisms.

Laparoscopic right hemicolectomy with 2D or 3D video system technology: systematic review and meta-analysis.

BACKGROUND: Standard laparoscopic colorectal surgery relies on 2D image systems in most centers. However, 3D vision has gained popularity and is used nowadays in a constantly rising number of units. Right hemicolectomy with intracorporeal anastomosis and lymph node dissection represents a surgical procedure that may benefit the most from 3D vision. The aim of the study was to summarize the available literature on the use of 2D vs. 3D video imaging in patients undergoing laparoscopic right hemicolectomy. METHODS: A comprehensive literature review was conducted including Medline/PubMed, Embase, and Scopus (PROSPERO registration number CRD 42022344764) through October 2022. The systematic review and meta-analysis were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The risk of bias was evaluated using the ROBINS-I tool. Certainty of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) guidelines and GRADEpro to develop a summary of evidence tables. Random-effects meta-analyses were conducted. RESULTS: Five observational retrospective studies (496 patients, 275 2D and 216 3D) were included. One study was rated as having a critical risk of bias; the remaining had low to moderate risk. 2D laparoscopic right hemicolectomy patients showed longer anastomotic time in 3/3 studies (MD = 3.32; 95%CI, 1.58-5.05; p = 0.002) and an upward trend in operative time in 4/5 studies (MD = 9.98; 95%CI, -1.42, 21.37; p = 0.086) compared to 3D. The two image video systems had similar short-term outcomes, including the number of lymph nodes harvested (MD = -0.67; 95%CI, -2.47, 1.13; p = 0.47), morbidity (OR post-operative complications = 1.12; 95%CI, 0.71-1.77; p = 0.62), and length of stay (MD = 0.27; 95%CI, -0.59, 1.13; p = 0.9). CONCLUSIONS: 2D and 2D laparoscopic right hemicolectomy had similar complications rate, with a shorter anastomotic time along with a downward trend in overall operative time for 3D. Larger prospective randomized trials are awaited before definitive conclusions can be drawn.

Does 3D laparoscopic video technology affect long-term survival in right hemicolectomy for cancer compared to standard 2D? A propensity score study.

BACKGROUND: There are few studies focused on the short-term results of laparoscopic right hemicolectomy performed with 2D (two-dimension) or 3D (three-dimension) video technology and none on the oncologic effects. The aim of the study was to assess the long-term results of laparoscopic right hemicolectomy (LRH) with intracorporeal anastomosis using 3D or 2D video in patients with right colon cancer with at least three years of oncologic follow-up. METHODS: Data from patients undergoing laparoscopic right hemicolectomy (LRH) with intracorporeal anastomosis for cancer in an 11-year period (June 2008-June 2019) and ≥ 3 years of follow-up were prospectively collected. Surgical procedures were performed by two expert laparoscopic surgeons. RESULTS: 111 patients were included in the study: 56 (50.5%) in the 3D group and 55 (49.5%) in the 2D group. Tumor stage and number of lymph nodes harvested were similar. Overall and disease-free survival were not different in the two groups. Local recurrence occurred in none of the patients, and distant metachronous metastases were similar in the two groups. A propensity score weighting approach was used to account for potential confounding related to patients' nonrandom allocation to the 2 groups. The effects of the intervention on postoperative outcomes were assessed with a weighted regression approach. CONCLUSIONS: Laparoscopic 3D technology allows similar oncological results as 2D vision in LRH with intracorporeal anastomosis. Larger prospective randomized studies might confirm these results in the long-term follow-up.

Which video technology brings the higher cognitive burden and motion sickness in laparoscopic colorectal surgery: 3D, 2D-4 K or 3D-4 K? a propensity score study.

BACKGROUND: Technological development has offered laparoscopic colorectal surgeons new video systems to improve depth perception and perform difficult task in limited space. The aim of this study was to assess the cognitive burden and motion sickness for surgeons during 3D, 2D-4 K or 3D-4 K laparoscopic colorectal procedures and to report post-operative data with the different video systems employed. METHODS: Patients were assigned to either 3D, 2D-4 K or 3D-4 K video and two questionnaires (Simulator Sickness Questionnaire-SSQ- and NASA Task Load Index -TLX) were used during elective laparoscopic colorectal resections (October 2020-August 2022) from two operating surgeons. Short-term results of the operations performed with the three different video systems were also analyzed. RESULTS: A total of 113 consecutive patients were included: 41 (36%) in the 3D Group (A), 46 (41%) in the 3D-4 K Group and 26 (23%) in the 2D-4 K Group (C). Weighted and adjusted regression models showed no significant difference in cognitive load amongst the surgeons in the three groups of video systems when using the NASA-TLX. An increased risk for slight/moderate general discomfort and eyestrain in the 3D-4 K group compared with 2D-4 K group (OR = 3.5; p = 0.0057 and OR = 2.8; p = 0.0096, respectively) was observed. Further, slight/moderate difficulty focusing was lower in both 3D and 3D-4 K groups compared with 2D-4 K group (OR = 0.4; p = 0.0124 and OR = 0.5; p = 0.0341, respectively), and higher in the 3D-4 K group compared with 3D group (OR = 2.6; p = 0.0124). Patient population characteristics, operative time, post-operative staging, complication rate and length of stay were similar in the three groups of patients. CONCLUSIONS: 3D and 3D-4 K systems, when compared with 2D-4 K video technology, have a higher risk for slight/moderate general discomfort and eyestrain, but show lower difficulty focusing. Short post-operative outcomes do not differ, whichever imaging system is used.

Prognostic role of platelet-to-lymphocyte ratio, neutrophil-to-lymphocyte, and lymphocyte-to-monocyte ratio in operated rectal cancer patients: systematic review and meta-analysis.

BACKGROUND: Inflammation plays an important role in tumor growth. Novel serum blood biomarkers, including neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR), have been proposed as useful prognostic indexes in cancer patients. However, their role in rectal cancer is controversial. METHODS: A comprehensive literature review was conducted including MEDLINE/Pubmed, EMBASE, SCOPUS, and the Cochrane Database of Systematic Reviews through May 2022. The systematic review and meta-analysis were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Quality was appraised with the Methodological Index for Non-Randomized Studies (MINORS) tool. Aim of the study was to summarize available literature on PLR, NLR, and LMR in patients with rectal cancer undergoing resection. RESULTS: Forty-seven observational studies (14,205 patients) were included; there were 42 retrospective and 5 prospective cohort studies with an average MINORS score of 14.6 (range: 12-18). Worse overall survival was associated with high NLR (HR 1.81; 95%CI 1.52-2.15; p < 0.001), high PLR (HR 1.24; 95%CI 1.06-1.46; p = 0.009), and low LMR (HR 0.67; 95%CI 0.49-0.91; p = 0.01). High NLR and low LMR were also associated with disease-free-survival (HR 1.68; 95%CI 1.35-2.08; p < 0.001 and HR 0.71; 95%CI 0.58-0.87; p < 0.001, respectively). CONCLUSIONS: NLR, PLR, and LMR are independent clinical predictors for overall survival in patients with rectal cancer treated with curative surgery. NLR and LMR are also good predictors for disease free survival. These biomarkers, which are readily available, appear optimal prognostic indexes and may help clinicians predict the prognosis of rectal cancer and develop individualized treatment strategies.

Preoperative Prognostic Nutritional Index was not predictive of short-term complications after laparoscopic resection for rectal cancer.

BACKGROUND AND AIM: Prognostic Nutritional Index (PNI) is a useful tool to predict short-term results in patients undergoing surgery for gastrointestinal cancer. Few studies have addressed this issue in colorectal cancer or specifically in rectal cancer. We evaluated the prognostic relevance of preoperative PNI on morbidity of patients undergoing laparoscopic curative resection for rectal cancer (LCRRC). METHODS: PNI data and clinico-pathological characteristics of LCRRC patients (June 2005-December 2020) were evaluated. Patients with metastatic disease were excluded. Postoperative complications were evaluated using the Clavien-Dindo classification. RESULTS: A total of 182 patients were included in the analysis. Median preoperative PNI was 36.5 (IQR 32.8-41.2). Lower PNI was associated with females (p=0.02), older patients (p=0.0002), comorbidity status (p<0.0001), and those who did not receive neoadjuvant treatment (p=0.01). Post-operative complications occurred in 53 patients (29.1%), by the Clavien-Dindo classification: 40 grades I-II and 13 grades III-V. Median preoperative PNI was 35.0 (31.8-40.0) in complicated patients and 37.0 (33.0-41.5) in uncomplicated patients (p=0.09). PNI showed poor discriminative performance regarding postoperative morbidity (AUC 0.57) and was not associated with postoperative morbidity (OR 0.97) at multivariable analysis. CONCLUSIONS: Preoperative PNI was not associated with postoperative morbidity after LCRRC. Further research should focus on different nutritional indicators or hematological/immunological biomarkers.

Missing the main actor: Intra-operative diagnosis of agenesis of the gallbladder - When late is not 'too' late.

Agenesis of the gallbladder (AGB) without extrahepatic biliary atresia is a rare congenital disease. Ultrasound (US) examination can be misleading and reveal a contracted shrunken gallbladder when there is not any and the patient in most cases is taken to the OR for a standard cholecystectomy. We describe the case of a 54-year-old female with colicky right upper abdominal pain with nausea. US revealed a contracted scleroatrophic gallbladder and the patient was listed for laparoscopic cholecystectomy. At laparoscopy, despite careful search, the gallbladder was never visualised, and the suspicion of AGB was raised. An intra-operative cholangiography confirmed the hypothesis. The post-operative recovery was uneventful, and abdominal computed tomography scan failed to show the presence of gallbladder, therefore confirming the diagnosis of AGB. Lack of awareness of this condition among radiologists and surgeons is the main reason for unnecessary operations and potentially damages to the biliary tract.

Dynamic Control of a Multistate Chiral Supramolecular Polymer in Water.

Natural systems transfer chiral information across multiple length scales through dynamic supramolecular interaction to accomplish various functions. Inspired by nature, many exquisite artificial supramolecular systems have been developed, in which controlling the supramolecular chirality holds the key to completing specific tasks. However, to achieve precise and non-invasive control and modulation of chirality in these systems remains challenging. As a non-invasive stimulus, light can be used to remotely control the chirality with high spatiotemporal precision. In contrast to common molecular switches, a synthetic molecular motor can act as a multistate chiroptical switch with unidirectional rotation, offering major potential to regulate more complex functions. Here, we present a light-driven molecular motor-based supramolecular polymer, in which the intrinsic chirality is transferred to the nanofibers, and the rotation of molecular motors governs the chirality and morphology of the supramolecular polymer. The resulting supramolecular polymer also exhibits light-controlled multistate aggregation-induced emission. These findings present a photochemically tunable multistate dynamic supramolecular system in water and pave the way for developing molecular motor-driven chiroptical materials.

Chemoradiation vs. local excision in the management of early squamous cell carcinoma of the anus: a systematic review.

PURPOSE: Squamous cell carcinoma of the anus (SCCA) suffers a constant increase each year in the last decades. Recent studies suggested the possibility of local excision (LE) as an option for early-stage SCAC patients. This systematic review aims to summarize the available evidence on the comparison of LE vs. chemoradiotherapy (CRT) in the treatment of early SCCA patients. METHODS: We conducted a literature review including MEDLINE/PubMed, EMBASE, SCOPUS, clinicaltrials.gov, and the Cochrane Database of Systematic Reviews through June 2022. MOOSE guidelines were followed. We used the methodological index for non-randomized studies (MINORS) tool to assess quality. Data on survival and procedure-associated costs were extracted. RESULTS: Four retrospective studies including 3323 patients were included. They were all comparative retrospective cohort studies (three were registry-based studies, either NCDB or SEER) with a MINORS score of 16-19 points. Overall survival (OS) was comparable between LE and CRT patients in three studies, with a 5-year OS of 85.3-100% in LE patients and 85-91.6% in CRT patients. One study investigated cancer-specific survival (CSS) and reported similar 5-year CSS in LE (98%) and CRT patients (96%). One investigated progression-free survival (PFS) and did not report any statistically significant difference in 5-year PFS between LE (91%) and CRT patients (83%). Only one study considered the mean costs associated with the two approaches (29,210 USD with LE and 46,350 USD with CRT). CONCLUSIONS: LE may potentially be considered a valid alternative to CRT for patients with early-stage SCAA. Results of prospective randomized long-term trials comparing LE with CRT are warranted to draw definitive conclusions and consider LE as a true cost-effective strategy for T1N0 SCCA with similar oncologic results offered by CRT, which-to date-remains the "gold standard." PROSPERO REGISTRATION: CRD42022338750.

Internal hernia following laparoscopic anterior resection for cancer: higher prevalence than expected of an under-reported complication.

BACKGROUND: Internal hernia (IH) after laparoscopic colorectal surgery is a potentially severe complication. It may go undiagnosed in patients having their abdominal CT scan during oncologic follow-up. We evaluated the occurrence of IH on CT scans after laparoscopic curative resection for rectal cancer (LRRC) and routine closure of the mesenteric defect. METHODS: Data from 189 consecutive patients undergoing elective curative LRRC in a 14-year period (June 2005-june 2019) were prospectively collected. Only patients with abdominal CT scans, performed as routine oncologic follow-up, between 3 months and 7 years post-operatively were included in the study and reviewed by a surgeon and a radiologist. RESULTS: A total of 161 patients were eligible for the study with a median age of 69 years (IQR: 59-77) at surgery. They had abdominal follow-up CT scans at a median of 39.5 months (IQR: 12.8-62.7) after surgery. The prevalence of IH was 11.2% (18/161 patients). Of the 18 patients, 15 (83.3%) were fully asymptomatic, 2 (11.1%) reported chronic abdominal discomfort (including mostly nausea and colicky pain) during their oncologic follow-up (however, IH was not suspected neither prompted additional investigations), and 1 (5.6%) was reoperated elsewhere for IH and acute small bowel obstruction. CONCLUSIONS: IH following LRRC is not uncommon, with a prevalence > 10% in our experience. Most of these patients remain fully asymptomatic, but in a few patients, IH might be responsible for some symptoms or require reoperation. Awareness of this complication is important, given the potential risk of acute small bowel obstruction.

Thiol-free self-assembled oligoethylene glycols enable robust air-stable molecular electronics.

Self-assembled monolayers (SAMs) are widely used to engineer the surface properties of metals. The relatively simple and versatile chemistry of metal-thiolate bonds makes thiolate SAMs the preferred option in a range of applications, yet fragility and a tendency to oxidize in air limit their long-term use. Here, we report the formation of thiol-free self-assembled mono- and bilayers of glycol ethers, which bind to the surface of coinage metals through the spontaneous chemisorption of glycol ether-functionalized fullerenes. As-prepared assemblies are bilayers presenting fullerene cages at both the substrate and ambient interface. Subsequent exposure to functionalized glycol ethers displaces the topmost layer of glycol ether-functionalized fullerenes, and the resulting assemblies expose functional groups to the ambient interface. These layers exhibit the key properties of thiolate SAMs, yet they are stable to ambient conditions for several weeks, as shown by the performance of tunnelling junctions formed from SAMs of alkyl-functionalized glycol ethers. Glycol ether-functionalized spiropyrans incorporated into mixed monolayers lead to reversible, light-driven conductance switching. Self-assemblies of glycol ethers are drop-in replacements for thiolate SAMs that retain all of their useful properties while avoiding the drawbacks of metal-thiolate bonds.

Structural Transitions During Formation and Rehydration of Proton Conducting Polymeric Membranes.

Knowledge of the transitions occurring during the formation of ion-conducting polymer films and membranes is crucial to optimize material performances. The use of non-destructive scattering techniques that offer high spatio-temporal resolution is essential to investigating such structural transitions, especially when combined with complementary techniques probing at different time and spatial scales. Here, a simultaneous multi-technique study is performed on the membrane formation mechanism and the subsequent hydration of two ion-conducting polymers, the well-known commercial Nafion and a synthesized sulfonated poly(phenylene sulfide sulfone) (sPSS). The X-ray data distinguish the multi-stage processes occurring during drying. A sol-gel-membrane transition sequence is observed for both polymers. However, while Nafion membrane evolves from a micellar solution through the formation of a phase-separated gel, forming an oriented supported membrane, sPSS membrane evolves from a solution of dispersed polyelectrolyte chains via formation of an inhomogeneous gel, showing assembly and ionic phase separation only at the end of the drying process. Impedance spectroscopy data confirm the occurrence of the sol-gel transitions, while gel-membrane transitions are detected by optical reflectance data. The simultaneous multi-technique approach presented here can connect the nanoscale to the macroscopic behavior, unraveling information essential to optimize membrane formation of different ion-conducting polymers.

Two-dimensional (2-D) vs. three-dimensional (3-D) laparoscopic right hemicolectomy with intracorporeal anastomosis for colon cancer: comparison of short-term results.

BACKGROUND: There are few reports comparing safety and efficacy of 2-D and 3-D video technology in laparoscopic right hemicolectomy. The aim of the study was to assess the short-term results of laparoscopic right hemicolectomy (LHR) with intracorporeal anastomosis with 2-D/3-D video in patients with right colon cancer. METHODS: Data from 239 patients undergoing LRH for cancer in a 14-year period (June 2005-January 2020) were prospectively collected. Surgical procedures were performed by two expert laparoscopic surgeons. RESULTS: One hundred and fourteen patients were included in the study: 55 (48.2%) operated with 2-D and 59 (51.8%) with 3-D video. Tumor site and postoperative stage distribution were similar. Mean operative time was comparable in the two groups (159.0 ± 48.8 min vs. 17.06 ± 36.0 min, p = ns, group 2-D and 3-D, respectively). Group 3-D patients had a similar percentage of associated procedures (44.1% vs. 29.1%, p = ns). Intraoperative complications were nil in both groups, while postoperative complications were similar (30.9% 2-D vs 25.4% 3-D, p = ns). The mean number of lymph nodes retrieved was similar in group 3-D (26.0 ± 14.6 vs. 22.9 ± 9.3, p = ns) and the length of stay was comparable in 3-D and 2-D patients (8.4 ± 2.6 vs. 9.1 ± 3.3 days, respectively, p = ns). CONCLUSIONS: Laparoscopic 3-D vision is as equally effective as 2-D vision in LRH with intracorporeal anastomosis, with a similar proportion of associated procedures and number of lymph nodes retrieved in the same operative time. Further prospective larger randomized studies are necessary to verify if LRH with 3-D video can reduce postoperative complications, compared to 2-D video.

Prevalence of internal hernia following laparoscopic colorectal surgery: single-center report on 1300 patients.

BACKGROUND: Internal hernia (IH) is an infrequent complication following colorectal resection with minimally invasive technique. The real prevalence is difficult to define and there are only few large series reporting data on this complication, often focusing only on left-sided resections. Aim of the study was to evaluate the occurrence of IH following laparoscopic colorectal resection (LCR), reporting clinical presentation and treatment. METHODS: Data from 1297 patients undergoing elective LCR for cancer or benign disease in a 15-year period (June 2005-March 2020) were prospectively collected. A database query was performed to search for small bowel obstructions requiring reintervention. RESULTS: Five patients presented symptomatic IH (prevalence = 0.38%) and required reintervention. The preceding surgical procedure was left hemicolectomy for diverticular disease in all patients. The mesenteric defect had been originally closed in 4/5 patients. The median time interval between initial surgery and the occurrence of IH was 1 (range: 0.3-10) month. In all cases a small bowel loop was found herniating through the mesocolic defect. Small bowel resection was required in one patient only. The median hospital stay following reintervention was 7 (range: 4-17) days. CONCLUSIONS: IH following LCR is a rare but severe complication, potentially leading to death, if not promptly diagnosed and treated. Awareness of this complication, early recognition, and proper diagnostic and therapeutic management is mandatory allowing laparoscopic approach and often avoiding small bowel resection.

Reversibly Photo-Modulating Mechanical Stiffness and Toughness of Bioengineered Protein Fibers.

Light-responsive materials have been extensively studied due to the attractive possibility of manipulating their properties with high spatiotemporal control in a non-invasive fashion. This stimulated the development of a series of photo-deformable smart devices. However, it remained a challenge to reversibly modulate the stiffness and toughness of bulk materials. Here, we present bioengineered protein fibers and their optomechanical manipulation by employing electrostatic interactions between supercharged polypeptides (SUPs) and an azobenzene (Azo)-based surfactant. Photo-isomerization of the Azo moiety from the E- to Z-form reversibly triggered the modulation of tensile strength, stiffness, and toughness of the bulk protein fiber. Specifically, the photo-induced rearrangement into the Z-form of Azo possibly strengthened cation-π interactions within the fiber material, resulting in an around twofold increase in the fiber's mechanical performance. The outstanding mechanical and responsive properties open a path towards the development of SUP-Azo fibers as smart stimuli-responsive mechano-biomaterials.

Molecular packing structure of fibrin fibers resolved by X-ray scattering and molecular modeling.

Fibrin is the major extracellular component of blood clots and a proteinaceous hydrogel used as a versatile biomaterial. Fibrin forms branched networks built of laterally associated double-stranded protofibrils. This multiscale hierarchical structure is crucial for the extraordinary mechanical resilience of blood clots, yet the structural basis of clot mechanical properties remains largely unclear due, in part, to the unresolved molecular packing of fibrin fibers. Here the packing structure of fibrin fibers is quantitatively assessed by combining Small Angle X-ray Scattering (SAXS) measurements of fibrin reconstituted under a wide range of conditions with computational molecular modeling of fibrin protofibrils. The number, positions, and intensities of the Bragg peaks observed in the SAXS experiments were reproduced computationally based on the all-atom molecular structure of reconstructed fibrin protofibrils. Specifically, the model correctly predicts the intensities of the reflections of the 22.5 nm axial repeat, corresponding to the half-staggered longitudinal arrangement of fibrin molecules. In addition, the SAXS measurements showed that protofibrils within fibrin fibers have a partially ordered lateral arrangement with a characteristic transverse repeat distance of 13 nm, irrespective of the fiber thickness. These findings provide fundamental insights into the molecular structure of fibrin clots that underlies their biological and physical properties.