Effects of acute normovolemic hemodilution and allogeneic blood transfusion on postoperative complications of oral and maxillofacial flap reconstruction: a retrospective study.

OBJECTIVE: Patients undergoing oral and maxillofacial flap reconstruction often need blood transfusions due to massive blood loss. With the increasing limitations of allogeneic blood transfusion (ABT), doctors are considering acute normovolemic hemodilution (ANH) because of its advantages. By comparing the differences in the (Δ) blood indices and postoperative complications of patients receiving ABT or ANH during the reconstruction and repair of oral and maxillofacial tumor flaps, this study's purpose was to provide a reference for the clinical application of ANH. METHODS: The clinical data of 276 patients who underwent oral and maxillofacial flap reconstruction from September 25, 2017, to October 11, 2021, in the Department of Oral and Maxillofacial Surgery, Sun Yat-sen Memorial Hospital, were retrospectively analyzed. According to the intraoperative blood transfusion mode, the patients were divided into two groups: ABT and ANH. The differences in the (Δ) blood indices and the incidence of postoperative complications between the groups were analyzed. RESULTS: Among the 276 patients who had ANH (124/276) and ABT (152/276), there were no differences in (Δ) Hb, (Δ) PT, or (Δ) FIB (P > 0.05), while (Δ) WBC, (Δ) PLT, (Δ) APTT and (Δ) D-dimer were significantly different (P < 0.05). The blood transfusion method was not an independent factor for flap crisis (P > 0.05). The wound infection probability in patients with high post-PTs was 1.953 times greater than that in patients with low post-PTs (OR = 1.953, 95% CI: 1.232 ∼ 3.095, P = 0.004). A normal or overweight BMI was a protective factor for pulmonary infection, and the incidence of pulmonary infection in these patients was only 0.089 times that of patients with a low BMI (OR = 0.089, 95% CI: 0.017 ∼ 0.462). Moreover, a high ASA grade promoted the occurrence of pulmonary infection (OR = 6.373, 95% CI: 1.681 ∼ 24.163). The blood transfusion mode (B = 0.310, ß = 0.360, P < 0.001; ANH: ln hospital stay = 2.20 ± 0.37; ABT: ln hospital stay = 2.54 ± 0.42) improved the length of hospital stay. CONCLUSION: Preoperative and postoperative blood transfusion (Δ) Hb, (Δ) PT, and (Δ) FIB did not differ; (Δ) WBC, (Δ) PLT, (Δ) APTT, and (Δ) D-dimer did differ. There was no difference in the effects of the two blood transfusion methods on flap crisis, incision infection or lung infection after flap reconstruction, but ANH resulted in a 3.65 day shorter average hospital stay than did ABT.

Cellulose nanocrystals in cancer diagnostics and treatment.

Cancer is currently a major threat to public health, being among the principal causes of death to the global population. With carcinogenesis mechanisms, cancer invasion, and metastasis remaining blurred, cancer diagnosis and novel drug delivery approaches should be developed urgently to enable management and treatment. A dream break-through would be a non-invasive instantaneous monitoring of cancer initiation and progression to fast-track diagnosis for timely specialist treatment decisions. These innovations would enhance the established treatment protocols, unlimited by evasive biological complexities during tumorigenesis. It is therefore contingent that emerging and future scientific technologies be equally biased towards such innovations by exploiting the apparent properties of new developments and materials especially nanomaterials. CNCs as nanomaterials have undisputable physical and excellent biological properties that enhanced their interest as biomedical materials. This article therefore highlights CNCs utility in cancer diagnosis and therapy. Their extraction, properties, modification, in-vivo/in-vitro medical applications, biocompatibility, challenges and future perspectives are precisely discussed.

Multi-analysis of chemical transformations of lignin macromolecules from waterlogged archaeological wood.

A large number of archaeological wooden building poles have been excavated from the Hai Menkou site (Yunnan province, China). Lignin can be transformed and altered accompanied with significant loss of carbohydrates during this process. Elucidation of chemical and structural transformations of lignin is of primary importance for understanding both the nature of degradation processes and the structure of waterlogged archaeological wood, and crucial for developing proper consolidation technology and restoring artifacts of historical and cultural value. In this study, state-of-the-art analytical techniques, including SEM, FT-IR, XRD, CP-MAS 13C NMR, 2D-HSQC NMR, 31P-NMR, CRM, GPC and TG analysis, were all employed to elucidate the structural characteristics of lignin in waterlogged and reference Pinus wood. The results interpreted by NMR analysis demonstrated the depolymerization of lignin via cleavage of ß-O-4, ß-5, -OCH3 and some LCC linkages, leading to a higher amount of free phenol OH groups in the lignin from the ancient waterlogged wood as compared to that of the reference wood. Microscopically, it was found that extensive degradation of carbohydrates in cell walls was mainly occurred in secondary cell walls, while the lignin concentrations were relatively increased in CCML and S regions in the plant cell wall of the ancient wood.

Electrospun PEGylated PLGA nanofibers for drug encapsulation and release.

We report the fabrication of electrospun nanofibers of polyethylene glycol (PEG)-modified poly (lactic-co-glycolic acid) (PLGA) with a fast release profile for biomedical applications. In this work, PLGA was first covalently modified with methoxy poly (ethylene glycol) amine (mPEG-NH2). The formed PEGylated PLGA (PLGA-PEG) was then mixed with a model drug amoxicillin (AMX) for subsequent fabrication of drug-loaded electrospun nanofibers. The synthesized PLGA-PEG conjugate and the formed drug-loaded PLGA-PEG nanofibers were characterized using different techniques. We show that the modification of PEG does not lead to an appreciable change in the uniform and smooth morphology of PLGA nanofibers. Importantly, the PEGylation modification affords a faster release profile of the encapsulated drug than pure PLGA nanofibers without PEGylation, which may be ascribed to the improved hydrophilicity of the PLGA-PEG polymer. Furthermore, antibacterial activity assay data reveal that the drug-loaded PLGA-PEG nanofibers are able to inhibit the growth of a model bacterium S. aureus. Finally, the hemocompatibility of the drug-loaded PLGA-PEG nanofibers was evaluated by hemolysis and anticoagulant assays, and the cytocompatibility of the fibers was confirmed by cell viability assay and cell morphology observation. We show that the formed drug-loaded PLGA-PEG nanofibers have an excellent hemocompatibility and cytocompatibility. The developed electrospun PLGA-PEG nanofibers may find various applications in the fields of tissue engineering and pharmaceutical sciences.

Electrospun hybrid nanofibers doped with nanoparticles or nanotubes for biomedical applications.

Electrospinning is a powerful technique to produce fibers with a diameter ranging from tens of nanometers to several micrometers. Compared with single-component nanofibers, composite or hybrid nanofibers are promising due to the unique properties possessed by both the host and the guest materials. Doping nanoparticles (NPs) or nanotubes (NTs) have excellent optical, mechanical, electrical or catalytic properties within polymer nanofibers, which makes it possible to produce functional nanofibers with promising applications. In this review, followed by a brief introduction of basic theory of electrospinning techniques, we give a literature survey of the NP- or NT-doped electrospun polymer nanofibers in terms of the producing methods and potential applications in the fields of tissue engineering, wound dressing and drug-delivery systems. Some of the aspects related to the improved protein adsorption capability, mechanical durability and, thus, improved cell attachment and proliferation of the NT-doped polymer nanofibers, as well as the significantly decreased burst-release profile of the NT-doped polymer nanofibers used as drug-delivery systems are discussed.

Synthesis and grafting of folate-PEG-PAMAM conjugates onto quantum dots for selective targeting of folate-receptor-positive tumor cells.

We report the design and synthesis of folate-poly(ethylene glycol)-polyamidoamine (FPP)-functionalized CdSe/ZnS quantum dots (QDs), in which the QD plays a key role in imaging, whereas the folate-poly(ethylene glycol) (PEG) conjugates of the polyamidoamine (PAMAM) dendrimer serve as a system targeted to folate receptors in tumor cells. Dendrimer ligands such as folate-PEG grafted PAMAM of generation 3.5 are found to encapsulate and solubilize luminescent QDs through direct ligand-exchange reactions. Because of membrane expression of FA receptors in tumor cells, this class of ligand-exchanged QDs is able to target tumor cells. We have evaluated FPP-coated QDs and QDs without folate in HeLa cells and shown that cellular uptake of FPP-coated QDs is more significant than that non folate QDs in vivo imaging experiment. In particular, QDs coated with FPP are initially bound to tumor cell surfaces, followed by slow endosomal escape and release into the tumor cells. These insights are important for the design and development of nanoparticle agents for optical detection of tumor cells and bio-imaging.