Tissue Surface Research Articles

In Situ Light-Source Delivery During 5-Aminulevulinic Acid-Guided High-Grade Glioma Resection: Spatial, Functional and Oncological Informed Surgery

Background/Objectives: 5-aminulevulinic acid (5-ALA)-guided surgery for high-grade gliomas remains a challenge in neuro-oncological surgery. Inconsistent fluorescence visualisation, subjective quantification and false negatives due to blood, haemostatic agents or optical impediments from the external light source are some of the limitations of the present technology. Methods: The preliminary results from this single-centre retrospective study are presented from the first 35 patients operated upon with the novel Nico Myriad Spectra System©. The microdebrider (Myriad) with an additional in situ light system (Spectra) can alternately provide white and blue light (405 nm) to within 15 mm of the tissue surface to enhance the morphology of the anatomical structures and the fluorescence of the pathological tissues. Results: A total of 35 patients were operated upon with this new technology. Eight patients (22.85%) underwent tubular retractor-assisted minimally invasive parafascicular surgery (tr-MIPS). The majority had high-grade gliomas (68.57%). Fluorescence was identified in 30 cases (85.71%), with residual fluorescence in 11 (36.66%). The main applications were better white–blue light alternation and visualisation during tr-MIPS, increase in the extent of resection at the border of the cavity, identification of satellite lesions in multifocal pathology, the differentiation between radionecrosis and tumour recurrence in redo surgery and the demarcation between normal ependyma versus pathological ependyma in tumours infiltrating the subventricular zone. Conclusions: This proof-of-concept study confirms that the novel in situ light-source delivery technology integrated with the usual intraoperative armamentarium provides a spatially, functionally and oncologically informed framework for glioblastoma surgery. It allows for the enhancement of the morphology of anatomical structures and the fluorescence of pathological tissues, increasing the extent of resection and, possibly, the prognosis for patients with high-grade gliomas.

Reducing Cardiovascular Risk in HIV: The Unseen Impact of Visceral Fat

While modern antiretroviral therapy (ART) for people with HIV (PWH) increases life expectancy, there is still an increased risk of developing cardiovascular disease (CVD) in this population. As one factor associated with this increased risk is excess visceral abdominal fat (EVAF), the Visceral Adiposity Measurement and Observations Study (VAMOS) aimed to assess the impact of EVAF on CVD risk in PWH taking modern ART. Participants were grouped according to visceral adipose tissue (VAT) surface area <130 cm2 (non-EVAF group) or ≥130 cm2 (EVAF group), quantified by CT scan. Findings presented at IDWeek 2024 revealed significant differences between EVAF and non-EVAF groups in 10-year atherosclerotic CVD (ASCVD) risk score, as well as many of their individual components. VAMOS also showed correlations between increasing VAT surface area and increasing 10-year ASCVD risk score and insulin resistance measures. Accordingly, VAT may represent a targetable factor to reduce ASCVD risk. Also shown was an inverse relationship between growth hormone (GH) levels and VAT surface area. As GH reductions related to obesity are associated with elevated CVD risk, increasing GH levels may consequently reduce ASCVD risk score. Analysis of two Phase III trials of the GH-releasing hormone (GHRH) analogue tesamorelin, which can significantly reduce VAT in PWH, was also presented at IDWeek 2024. A significant overall trend in 10-year ASCVD risk score reduction was shown in tesamorelin-treated participants, around half of which were already taking lipid lowering therapies. This suggests a benefit of targeting and reducing EVAF to further impact ASCVD risk.

Adaptable Hydrogel with Strong Adhesion of Wet Tissue for Long-Term Protection of Periodontitis Wound.

Periodontitis is a severe gum infection characterized by inflammation of the tissues surrounding the teeth. The disease is challenging to manage due to its exposure to a wet and dynamic oral environment, where conventional hydrogels often suffer from weak adhesion, short residence time, and vulnerability to bacterial invasion. In this study, an innovative hydrogel system based on in situ light curing is proposed. The hydrogel precursor, comprising sodium alginate and a calcium ion network, is designed and adhere to the irregular and smooth surfaces of periodontal tissue before curing. Upon light irradiation, a second network polymerizes rapidly, establishing multiple interactions with the tissue, which enhances adhesion strength. Benefited from this engineering strategy, the hydrogelexhibits a low swelling rate, effectively mitigating adhesion loss in the moist oral environment. Additionally, the hydrogel demonstrates excellent long-lasting wet adhesion, maintaining its presence in periodontal tissue over 120 hours. It also serves as an effective physical barrier against bacterial invasion, achieving a blocking efficiency of 99.9%. This novel design concept offers a promising approach for developing advanced medical dressings for periodontitis, providing sustained therapeutic benefits.

Substantive Dimethicone-Based Mucoadhesive Coatings.

It is challenging to deliver therapeutics in the oral environment due to the wet surfaces, the nature of the mucosa and the potential for saliva washout. In this study, the development of a mucoadhesive dimethicone-based oral carrier system for adhesion to the hard tissue and mucosa in the mouth was examined. This study reports the viscosity and mucoadhesion of dimethicone based polymer blends. The viscosity of the materials was measured using a rheometer. The mucoadhesion of these materials was determined as the work of adhesion and peak tack force using the tensile test method with a texture analyzer. Materials were prepared with either calcium and phosphate salts or sodium fluoride as potential therapeutics for promoting remineralization and treating dentin hypersensitivity by mechanical occlusion. Scanning electron microscopy was used to look at mineral deposition on the surface of dental hard tissue after the application of the dimethicone-based formulations. The results of this study confirm the potential for using these dimethicone-based materials as mucoadhesive therapeutic delivery systems in the oral environment.

Microfracture Versus a Porcine-Derived Collagen-Augmented Chondrogenesis Technique for Treating Knee Cartilage Defects: Results at Midterm Follow-up.

Damaged cartilage can be treated using the creation of microfractures (MFxs) or the porcine-derived collagen-augmented chondrogenesis technique (C-ACT). To provide the midterm results of a multicenter randomized controlled trial comparing MFx and C-ACT for knee cartilage defects. Randomized controlled trial; Level of evidence, 1. The study cohort comprised 36 patients with medial femoral condyle cartilage defects who were followed up for 6 years with clinical and magnetic resonance imaging data (n = 14 treated with MFx alone, n = 22 treated with C-ACT). Clinical outcomes were assessed preoperatively and at 1, 2, and 6 years postoperatively using a visual analog scale (VAS) for pain, the Knee injury and Osteoarthritis Outcome Score (KOOS), and the International Knee Documentation Committee (IKDC) subjective score. Magnetic resonance imaging scans were performed preoperatively and at 1 and 6 years postoperatively, and the repaired cartilage tissue was evaluated using the magnetic resonance observation of cartilage repair tissue (MOCART) score. The repaired tissue/reference cartilage ratio was quantified using T2 mapping. Adverse events during follow-up were also evaluated. In both groups, the VAS pain score improved and was maintained for 1, 2, and 6 years postoperatively compared with preoperatively (P < .05 for all). Although there were no significant differences between groups in the VAS pain, KOOS, or IKDC scores at any time point, the change in the IKDC-Activities of Daily Living subscore from preoperatively to 6 years postoperatively was better in the C-ACT group than the MFx group (P = .0423). At 6 years postoperatively, the MOCART assessment showed superior results regarding the surface of the repair tissue in the C-ACT group compared with the MFx group (P = .0288). There were no differences between the groups in the total MOCART score or other subscores. The study results suggest that C-ACT has similar effects to MFx in improving pain, joint function, and imaging findings and may be superior to MFx in improving daily life function and improving the quality of the surface of the cartilage tissue. ClinicalTrials.gov identifier: NCT02539030.

Autofluorescence-guided Removal of Bacterial Biofilms from Tissues Using Cold Atmospheric Pressure Plasma (CAP).

Cold atmospheric pressure plasma (CAP) has the potential to completely remove biofilms from surfaces. The goal of this study is to employ the autofluorescence nature of bacterial biofilms to guide the removal of these biofilms using a CAP scalpel. Pseudomonas fluorescens biofilms, which produce a green fluorescence under 405 nm UV light, were grown on 12 chicken samples. The tissue model (chicken tissue) is placed on a motorized X-Y stage with the plasma discharge device directly above the sample. Fluorescent-guided CAP treatment of biofilm regions was carried out using a 1.37 lpm Ar/H2O plasma device with 39.5 × 54 mm2 dimension and a 1 * 0.6 mm2 plasma discharge outlet with discharge speed was 1 mm/s and sample distance of 4 mm. The discharge voltage and current were 3.24 kV and 1.2 mA respectively. Results based on analysis of the fluorescent images show that 97% biofilm removal; CFU analysis confirms that up to 99.98% of the bacteria are now absent from the tissue's surface. This is the first instance of two new applications: using cold atmospheric plasma (CAP) to remove bacterial biofilms from soft tissues and employing CAP in an image-guided procedure.

Comparison of holmium:yttrium-aluminium-garnet (YAG), thulium fiber laser, and pulsed thulium:YAG lasers on soft tissue: an ex vivo study.

To assess laser-tissue interactions through ablation, coagulation, and carbonisation characteristics in a non-perfused porcine kidney model between three pulsed lasers: holmium (Ho): yttrium-aluminium-garnet (YAG), thulium fiber laser (TFL), and pulsed thulium (p-Tm):YAG. A 150-W Ho:YAG, a 60-W TFL, and a 100-W p-Tm:YAG lasers were compared. The laser settings that can be set identically between the three lasers and be clinically relevant for prostate laser enucleation were identified and used on fresh, unfrozen porcine kidneys. Laser incisions were performed using stripped laser fibers of 365 and 550 μm, set at distances of 0 and 1 mm from the tissue surface at a constant speed of 2 mm/s. Histological analysis evaluated shape, depth, width of the incision, axial coagulation depth, and presence of carbonisation. Incision depths, widths, and coagulation zones were greater with Ho:YAG and p-Tm:YAG lasers than TFL. Although no carbonisation was found with the Ho:YAG and p-Tm:YAG lasers, it was common with TFL, especially at high frequencies. The shapes of the incisions and coagulation zones were more regular and homogeneous with the p-Tm:YAG laser and TFL than with Ho:YAG laser. Regardless of the laser used, short pulse durations resulted in deeper incisions than long pulse durations. Concerning the distance, we found that to be effective, TFL had to be used in contact with the tissue. Finally, 365-μm fibers resulted in deeper incisions, while 550-μm fibers led to wider incisions and larger coagulation zones. Histological analysis revealed greater tissue penetration with the p-Tm:YAG laser compared to the TFL, while remaining less than with Ho:YAG. Its coagulation properties seem interesting insofar as it provides homogeneous coagulation without carbonisation, while incisions remained uniform without tissue laceration. Thus, the p-Tm:YAG laser appears to be an effective alternative to Ho:YAG and TFL lasers in prostate surgery.

The heat transfer in skin tissues under the general two-temperature three-phase-lag model of heat conduction with a comparative study

In this paper, a new and more general model of heat conduction that depends on the drift velocity due to thermomass motion assumption will be established and will be applied to the skin tissue. Four different heat conduction models will be incorporated into a unified equation of heat conduction: the Pennes, Vernotte-Cattaneo, dual-phase-lag of Tzou, and the general two-temperature three-phase-lag of Youssef. The governing partial differential equations of the general two-temperature three-phase-lag model of bioheat conduction will be implemented and solved directly in the domain of the Laplace transformation. The numerical solutions of the Laplace transform will be calculated by executing the Tzou iteration formula. The ramp-type heat on the surface of the skin tissue will be considered as thermal loading. The conductive and dynamic temperature increment reactions have been studied and discussed with different values of ramp-time heat, characteristic length, and drift velocity parameters. The novelty of this work is to introduce some comparisons of the four under-studied bioheat conduction models and show the differences between them in the figures. The numerical results show that the ramp-time heat, drift velocity, and characteristic length parameters have major impacts on the increment of both dynamical and conductive temperature distributions.

A rapid and robust organ repair polyacrylamide/alginate adhesive hydrogel mediated via interfacial adhesion-trigger molecules

Adhesive hydrogels have been widely explored as tissue adhesives for wound sealing and repair. However, developing adhesive hydrogels with simple preparation techniques and strong adhesion to internal organs in a short time remains a challenge. In this study, we developed a strategy for robust and rapid tissue adhesion of internal organ sealing and repair by an interfacial adhesion-molecule triggered hydrogel system. In this system, polyphenol molecules act as adhesion-trigger reagents to achieve fast and strong adhesion of polyacrylamide/alginate hydrogels on the surface of wound tissue by rapidly forming abundant hydrogen bonds at the interface. The adhesion energy is significantly enhanced by 45 times under the mediation of polyphenol adhesion-trigger molecules, resulting in a robust (> 600 J m−2) tissue adhesion in just 30 s. This interfacial adhesion system demonstrates good biocompatibility, strong sealing performance on multiple organs (porcine heart, lung, stomach, and intestine), and excellent repair properties in gastric perforation wounds of rabbits in vivo. Moreover, immunocytochemical and transcriptomic analyses reveal that this interfacial adhesion system significantly promotes vascular regeneration and inhibits inflammatory responses during wound repairing. The proposed hydrogel provides a facile strategy for rapid and robust tissue adhesion, and shows potential applications in organ sealing and repair.

Section thickness is identical for the sliding microtome and rotary microtome under the continuous cooling device condition

To date, no report has compared section thickness (ST) between the sliding microtome (SM) and rotary microtome (RM). We used the ice pack (IP) condition, in which the paraffin block was not cooled during slicing, and a continuous cooling device (CCD) for continuous cooling during slicing. The ST was greater for the SM than the RM in the IP condition, but it was identical between the devices under the CCD condition. Thus, we used the CCD condition for subsequent studies. In formalin-fixed, paraffin-embedded (FFPE) fish sausage blocks, the ST of the tissue surface (T-surface) was significantly concaved compared to that of the paraffin surface (P-surface) for both microtomes. On the contrary, in FFPE human kidney blocks, ST did not differ between the T-surface and P-surface. Furthermore, the eosin-positive area of PAM-stained specimens was affected by ST, and the color tone of the thickest sample differed from that of the median or thinnest sample. Our data indicated that we should use CCD conditions to ensure that ST is uniform regardless of the type of microtome. In addition, for quantitative analysis, we should utilize ST measure equipment and specimens with a constant ST.

Simulating irregular symmetry breaking in gut cross sections using a novel energy-optimization approach in growth-elasticity

Growth-elasticity (also known as morphoelasticity) is a powerful model framework for understanding complex shape development in soft biological tissues. At each instant, by mapping how continuum building blocks have grown geometrically and how they respond elastically to the push-and-pull from their neighbors, the shape of the growing structure is determined from a state of mechanical equilibrium. As mechanical loads continue to be added to the system through growth, many interesting shapes, such as smooth wavy wrinkles, sharp creases, and deep folds, can form on the tissue surface from a relatively flatter geometry.Previous numerical simulations of growth-elasticity have reproduced many interesting shapes resembling those observed in reality, such as the foldings on mammalian brains and guts. In the case of mammalian guts, it has been shown that wavy wrinkles, deep folds, and sharp creases on the interior organ surface can be simulated even under a simple assumption of isotropic uniform growth in the interior layer of the organ. Interestingly, the simulated patterns are all regular along the tube’s circumference, with either all smooth or all sharp indentations, whereas some undulation patterns in reality exhibit irregular patterns and a mixture of sharp creases and smooth indentations along the circumference. Can we simulate irregular indentation patterns without further complicating the growth patterning?In this paper, we have discovered abundant shape solutions with irregular indentation patterns by developing a Rayleigh–Ritz finite-element method (FEM). In contrast to previous Galerkin FEMs, which solve the weak formulation of the mechanical-equilibrium equations, the new method formulates an optimization problem for the discretized energy functional, whose critical points are equivalent to solutions obtained by solving the mechanical-equilibrium equations. This new method is more robust than previous methods. Specifically, it does not require the initial guess to be near a solution to achieve convergence, and it allows control over the direction of numerical iterates across the energy landscape. This approach enables the capture of more solutions that cannot be easily reached by previous methods. In addition to the previously found regular smooth and non-smooth configurations, we have identified a new transitional irregular smooth shape, new shapes with a mixture of smooth and non-smooth surface indentations, and a variety of irregular patterns with different numbers of creases. Our numerical results demonstrate that growth-elasticity modeling can match more shape patterns observed in reality than previously thought.

Unlocking Toll-Like Receptors: Targeting Therapeutics for Respiratory Tract Infections and Inflammatory Disorders

Abstract: The Toll-like Receptors (TLRs) family has significantly enhanced the understanding of innate immune responses by identifying and responding to various microbes or host-derived organisms. TLRs contribute to these responses by increasing the levels of cytokines, interleukins, and other inflammatory mediators through multiple pathways. Located both intracellularly and on the surface of various cells and tissues, including vascular smooth muscles (VSMs) and myocardium cells, TLRs play distinct roles in innate immune activation, such as recognizing pathogen-associated molecular patterns (PAMPs) and activating downstream signaling pathways. In the context of COVID-19, TLRs are critically involved in the pathophysiology by mediating excessive inflammatory responses that exacerbate disease severity, influencing both the acute phase and long-term outcomes. It has been observed that inflammatory diseases such as atherosclerosis, viral myocarditis, and other comorbidities associated with the spread of COVID-19 have increased, although the exact mechanisms remain not fully understood. Nonetheless, there is evidence of TLR-mediated increased pro-inflammatory signaling by different mechanisms in these diseases. This review explains the role of TLRs in various inflammatory diseases related to COVID-19, including viral myocarditis, acute lung infections, and atherosclerosis. Furthermore, the review discusses various herbal drugs, such as Platycodon grandiflorum, Acanthopanax senticosus, Scutellaria baicalensis Georgi, and Engelhardia roxburghiana, and their mechanisms of action on TLRs, including NF-κB, MyD88-dependent, MyD88-independent pathways, and Plasmacytoid DCs. Enhanced clarity on TLRs' specific contributions to COVID-19 pathophysiology and stronger evidence supporting herbal interventions targeting TLRs could improve the impact and applicability of these findings in clinical settings.

Enhanced breast tumor localization with DRA antenna backscattering and GPR algorithm in microwave imaging

With the rapid rate of increasing breast cancer cases across the globe and restrictions of existing early stage detection techniques, microwave imaging based cancer and malignant cell diagnosing methodology is finding its way. Microwave imaging technology has higher accuracy of detection in the variation of tissue properties. In this article, a dielectric resonator based wide band antenna is designed and investigated for microwave imaging (MWI) of early breast cancer detection due to its improved accuracy. The designed antenna has compact size, broad frequency spectrum, high gain and broadside radiation characteristics. To attain the wider bandwidth from (6.5 GHz–12.5 GHz), two rectangular shaped dielectric slabs are used. Wide band microwave frequency band supports the high resolution images. A C-shaped defected ground structure is used to tune the impedance matching. Dielectric resonator based antenna has higher gain and reduces the squints in antenna impedance. Two-asymmetrical dielectric slabs contribute in the excitation of different resonating modes which in turn enhance the bandwidth. It also contributes to excite multiple resonance mode that in turn enhance the bandwidth. Antenna performance is first numerically and experimentally verified in free space. Then, simulation based performance is examined for the microwave imaging. Numerical phantom with equivalent tissue properties is designed with and without the tumor. Unhealthy cells have higher water percentage and larger dielectric constant as compared to healthy cells. It causes the different in the back scattered signal of antenna, which is analyzed to diagnose the tumor or cancer. Here, a maximum deviation of 16 dB is observed in the backscattered signal. Furthermore, surface of the breast tissue is scanned along the x-axis and y-axis at different angels. The collected signals are used to reconstruct the microwave image of the interior. Mean value data of backscattered signals is used to locate the existence of unhealthy cells and GPR algorithm is used to calculate the depth of a 4 mm tumor in breast tissue. Proposed structure has shown efficient performance for microwave imaging.

Application of the Raman fluorescence method to study the effects of chemical, physical and radiation factors on the mineralization of hard dental tissues

Objective. To study the effect of physical, chemical and radiation factors on the degree of mineralization of the hard dental tissues surface using spectroscopy. Materials and methods. The degree of mineralization of hard dental tissues was studied by the Raman spectroscopy using hardware-software complex InSpectrum M on the teeth removed according to clinical indications (in vitro): in varying degrees of moisture (dry and wet); before and after exposure to acid and remineralizing drug; before and after exposure to radiation Results. The data obtained demonstrated the difference in the indicators in dry (1801 [1800; 1802]) relative units, and moistened (591.5 [591; 592]) teeth. The mineralization of teeth according to Raman Intensity before exposure to citric acid, was (602 [601; 602]) rel. units, and after the exposure it was (152 [152; 153]) rel. units, after application of the cm-2 plate it was (423 [422; 423]) rel. units. The identified differences are reliable (p 0.001). Thus, it is confirmed that organic acids (citric acid) contribute to the enamel demineralization by more than two times, and the use of calcium-containing plates contributes to remineralization almost to the initial state. At the same time, there were no significant differences in the level of mineralization (according to the Raman method of fluorescence spectroscopy) in teeth before and after direct radiation exposure, regardless of dose (2 Gy, 70 Gy, 110 Gy) in any of the functional groups (incisors, canines, premolars, molars). Conclusions. 1. Raman-fluorescence spectroscopy has a high sensitivity and is capable of detecting mineralization, de- and re-mineralization of hard dental tissues. 2. It is recommended to determine the hard tooth tissues mineralization by Raman-fluorescence spectroscopy in a moistened rather than a dry form. 3. Organic acids contribute to the demineralization of enamel, and the use of calcium-containing plates promotes its remineralization. 4. Direct radiation exposure does not have a direct effect on the mineralization of the surface of the hard dental tissues. regardless of the dose applied in all functional groups (incisors, canines, premolars, molars), in all areas of the teeth (equator, cutting edge, gum border).

A bio-inspired Janus hydrogel patch facilitates oral ulcer repair by combining prolonged wet adhesion and lubrication

Oral ulcers, the most common type of mucosal lesion, are both highly prevalent and prone to recurrence. In the persistently moist environment of the oral cavity, current therapeutic patches face challenges such as short adhesion time, disruption by food particles and bacteria, and oral movements. To address these challenges, we develop a Janus patch, named ANSB, inspired by the multi-layered and asymmetric structure of natural mucosa, featuring a long-lasting adhesive layer and a lubricating layer. By eliminating the salivary barrier and leveraging covalent crosslinking between tissue surface amine groups and N-hydroxysuccinimide ester (NHS), the adhesive layer—composed of gelatin and acrylic acid—achieves rapid (≤ 30 s), strong (≥ 45 kPa), and durable (≥ 8 h) adhesion to wet buccal tissues. Furthermore, the efficient lubricating effect (COF = 0.02 ± 0.003) provided by zwitterions renders the lubricating layer of ANSB highly similar to natural mucosal tissue, effectively preventing bacterial invasion, secondary damage, and unintended adhesion. Additionally, the strong interlayer bonding and complementary mechanical properties are confirmed, resulting in a unified performance characterized by rapid wet adhesion, hydration lubrication, and enhanced mechanical strength. Importantly, ANSB treatment demonstrates a long-term protective barrier and superior therapeutic effects in rat oral ulcers, inhibiting pseudomembrane formation and accelerating tissue regeneration without causing secondary damage. Consequently, this distinctive Janus patch, characterized by prolonged adhesion, efficient lubrication, and simple preparation, holds significant potential for clinical oral ulcer treatment. Statement of SignificanceOral ulcers, with healing impeded by secondary injury and bacterial invasion due to the absence of protective barriers, are highly prevalent and recurrent. However, sustaining therapeutic materials and physical barriers in the highly dynamic and moist oral environment poses a considerable challenge. In this study, a Janus patch (ANSB) that integrated a soft wet adhesive layer and a tough lubricating layer was developed to reconstruct a new protective barrier thus preventing external stimuli such as secondary damage and bacterial infiltration. This innovative patch with high therapeutic potential for oral ulcers may offer a new way for ulcer treatment based on barrier protection.

Morphological Characterization of Tissue Destruction According to the Distance Between Holmium:YAG Laser Tip and Tissue Surface.

Little is known about the soft tissue destruction by holmium laser clinically used for holmium laser enucleation of the prostate (HoLEP), subject to the distance between the laser fiber tip and the tissue surface. We aimed to investigate the impact of the distance between the laser fiber tip and the phantom surface (DLP) on a soft tissue phantom (STP) in relation to the surgical modes of HoLEP. STP responses to the laser pulses produced by a commercial holmium:yttrium aluminum garnet (Holmium:YAG) laser at an output setting 2 J were observed at different values of the DLP (0, 1, 2, 3, and 4 mm) to look at (1) the single laser pulse-induced cavitation bubble and its penetration into the STP, (2) the STP destruction by a single pulse, (3) the STP destruction by 60 pulses repeated at 12 Hz, and (4) the thermal effect by the multiple pulses visualized on a thermosensitive bovine serum albumin (BSA) STP. We observed that the laser pulse produced a heated gas bubble in water centered at the laser fiber tip. The bubble shape depended on the DLP. The bubble completely penetrated into the STP at the DLP of 0 mm and the penetration decreased with the DLP. The size of the destruction of the STP by the laser pulses was shown to decrease as the DLP increased. Test with the BSA STP showed that, at the DLP of 3 mm, the destruction became insignificant while the thermal effects were still effective. We illustrated that soft tissue destruction by the Holmium:YAG laser is associated with cavitation effects. We provide for the first time experimental evidence for various surgical modes in HoLEP such as incision and hemostasis in relation to the DLP.

Combining Multiple Spectroscopic Techniques to Reveal the Effects of Staphylococcus aureus Infection on Human Bone Tissues.

Osteomyelitis (OM) and periprosthetic joint infections (PJIs) are major public health concerns in Western countries due to increased life expectancy. Infections usually occur due to bacterial spread through fractures, implants, or blood-borne transmission. The pathogens trigger an inflammatory response that hinders bone tissue regeneration. Treatment requires surgical intervention, which involves the precise removal of infected tissue, wound cleansing, and local and systemic antibiotic administration. Staphylococcus aureus (SA) is one of the most common pathogens causing infection-induced OM and PJIs. It forms antimicrobial-resistant biofilms and is frequently found in healthcare settings. In this proof-of-concept, we present an approach based on multiple spectroscopic techniques aimed at investigating the effects of SA infection on bone tissue, as well as identifying specific markers useful to detect early bacterial colonization on the tissue surface. A cross-section of a human femoral diaphysis, with negative-culture results, was divided into three parts, and the cortical and trabecular regions were separated from each other. Two portions of each bone tissue type were infected with SA for one and seven days, respectively. Multiple techniques were used to investigate the impact of the infection on bone tissue, Brillouin-Raman microspectroscopy and attenuated total reflection Fourier transform infrared spectroscopy were employed to assess and develop a new noninvasive diagnostic method to detect SA by targeting the bone of the host. The results indicate that exposure to SA infection significantly alters the bone structure, especially in the case of the trabecular type, even after just one day. Moreover, Raman spectral markers of the tissue damage were identified, indicating that this technique can detect the effect of the pathogens' presence in bone biopsies and pave the way for potential application during surgery, due to its nondestructive and contactless nature.

Optical Transparency Windows in Near-Infrared and Short-Wave Infrared for the Skin, Skull, and Brain: Fluorescence Bioimaging Using PbS Quantum Dots.

Fluorescence imaging (FI) employing near-infrared (NIR) light within the range of ~750-1350 nm enables biomedical imaging several millimeters beneath the tissue surface. More recent investigations into the short-wave IR (SWIR) transparency windows between ~1550-1870 and 2100-2300 nm highlight their superior capabilities. This research presents a comparison of IR-FI of PbS quantum dots, emitting at 990, 1310, and 1580 nm, through the mouse scalp skin, skull, and brain. The SWIR fluorescence is the most effectively transmitted signal, showing particularly significant enhancement when passing through the skull, which causes high light scattering. For the analysis of the imaging results and light propagation through the organs, their spectra of attenuation, absorption, and scattering coefficients are measured. In view of biomedical imaging, attenuation due to light scattering is a more destructive factor. Hence, the spatial resolution and imaging contrast can be improved by operating in SWIR due to decreased light scattering.

Chitosan-Based Composite Aerogel with a Rapid Tissue Hydration Layer-Triggered Response to Promote Hemostasis.

Aerogels exhibit poor adhesion to wet tissue surfaces, which is a significant factor that limits their hemostatic properties. In this work, we propose a new method for investigating aerogel hemostatic materials by introducing the concept of the 'rapid tissue hydration layer-triggered property' into the hemostatic material. A chitosan derivative (Csde) with a "swollen property" was prepared via an amide reaction, followed by the incorporation of the extracted bletilla striata complex (Bscai) into the chitosan derivative to fabricate the Bscai/Csde hemostatic material. The research results indicated that the Bscai/Csde hemostatic material exhibited a rapid tissue hydration layer-triggered response, outstanding hemostasis ability, as well as excellent hemocompatibility, antibacterial properties, and cytocompatibility. Additionally, the preparation method for the Bscai/Csde hemostatic material is straightforward, and the raw materials are readily available. Therefore, this study presents a novel method for developing a hemostatic material method, and the composite aerogel hemostatic material demonstrates considerable potential for future applications.

Four Different Build Angles in 3D-Printed Complete Denture Bases: A Comparative In Vitro Study

In this study, we aimed to investigate the differences in tissue surface adaptation and the variations in distances between reference points on the polished surfaces of 3D-printed denture bases produced at different build angles. The build angles were 0°, 30°, 60°, and 90°, with 15 denture bases printed for each angle. Using the Geomagic Control® software, a 3D best-fit alignment was conducted between the denture base tissue surface and the reference shape of the edentulous maxilla model to calculate the root mean square error. The distances between reference points on the polished surface were measured using digital calipers. A one-way analysis of variance was conducted for statistical analysis. The adaptation, as measured by the root mean square error, varied significantly among denture bases with different build angles. The distances between the anterior and posterior reference points of the polished surface were also significantly different. However, within the limitations of this study, the variations in adaptations and dimensional accuracy across different build angles were within clinically acceptable ranges. In clinical practice, the print angle can be adjusted based on factors such as printing time, resin consumption, and the number of denture bases being printed simultaneously.