Propeller Flap Reconstruction Following Pilonidal Cyst Excision: A Single-Center Experience With Same-Day Discharge.

INTRODUCTION: Reconstruction following pilonidal cyst resection must balance risk of recurrence, healing time, and resumption of functional routine. Propeller flaps provide a reliable and effective reconstructive option. This study highlights our experience with propeller flap reconstruction following pilonidal cyst resection and demonstrates the efficacy of same-day discharge. METHODS: A single-institution retrospective chart review was performed for propeller flap reconstructions completed from March 2018 to July 2022. Patient demographics, pilonidal cyst details, operative details, and postoperative outcomes were collected. Primary outcomes included flap survival, flap complications, and pilonidal disease recurrence. RESULTS: Twenty-eight outpatient propeller flap reconstructions following pilonidal cyst resections were identified in 26 patients, with two patients receiving a second propeller flap due to recurrence. Most patients were male (n = 15, 57.7%) with a mean age at time of index operation of 25.5 ± 5.8 years and mean body mass index of 26.5 ± 4.1 kg/m2. Mean symptom duration prior to index surgery was 39.3 months. Mean skin defect size following resection was 28.3 ± 15.3 cm2, with a mean flap size of 44.7 ± 35.5 cm2. Flap survival was 100% (n = 28), with five flaps (17.9%) experiencing minor wound complications and one patient (3.8%) requiring return to the operating room. Mean time to functional improvement was 24.0 ± 22.8 days. Pilonidal disease recurrence occurred in three patients (11.5%). Mean follow-up was 4.1 ± 5.4 months. CONCLUSIONS: Propeller flaps provide a successful and reliable reconstructive option for pilonidal disease defects. Because patients in our cohort experienced favorable outcomes and functional improvement, we advocate for same-day discharge in order to reduce hospital and patient burden.

Nanocrystal Assemblies: Current Advances and Open Problems.

We explore the potential of nanocrystals (a term used equivalently to nanoparticles) as building blocks for nanomaterials, and the current advances and open challenges for fundamental science developments and applications. Nanocrystal assemblies are inherently multiscale, and the generation of revolutionary material properties requires a precise understanding of the relationship between structure and function, the former being determined by classical effects and the latter often by quantum effects. With an emphasis on theory and computation, we discuss challenges that hamper current assembly strategies and to what extent nanocrystal assemblies represent thermodynamic equilibrium or kinetically trapped metastable states. We also examine dynamic effects and optimization of assembly protocols. Finally, we discuss promising material functions and examples of their realization with nanocrystal assemblies.

How severity and classification of pulmonary hypertension affect pregnancy outcomes: a systematic review and timeline.

Women with pulmonary hypertension (PH) have increased mortality during pregnancy and the peripartum period. An increasing number of publications suggest improvements in maternal outcomes, so we conducted a systematic review focusing on disease severity and maternal survival. After screening 9097 potential studies from 1967 to 2021, we identified 66 relevant publications. Outcomes improved continuously over time and mortality fell from 11.6% in studies published before 2015 to 8.2% in studies published after 2015. Mortality was lower in patients with mild disease (0.8%) than in those with Eisenmenger syndrome (26.2%) or idiopathic pulmonary arterial hypertension (7.4-24.0%). One major drawback of the published studies is that they define severity using echocardiographic-estimated pulmonary artery pressures, without considering more contemporary parameters. This systematic review provides new insights for preconception counseling on pregnancy risks related to PH and suggests that PH classification and severity should be carefully considered in determining an individual's pregnancy-associated risk.

Microscopic origin of tunable assembly forces in chiral active environments.

Across a variety of spatial scales, from nanoscale biological systems to micron-scale colloidal systems, equilibrium self-assembly is entirely dictated by-and therefore limited by-the thermodynamic properties of the constituent materials. In contrast, nonequilibrium materials, such as self-propelled active matter, expand the possibilities for driving the assemblies that are inaccessible in equilibrium conditions. Recently, a number of works have suggested that active matter drives or accelerates self-organization, but the emergent interactions that arise between solutes immersed in actively driven environments are complex and poorly understood. Here, we analyze and resolve two crucial questions concerning actively driven self-assembly: (i) how, mechanistically, do active environments drive self-assembly of passive solutes? (ii) Under which conditions is this assembly robust? We employ the framework of odd hydrodynamics to theoretically explain numerical and experimental observations that chiral active matter, i.e., particles driven with a directional torque, produces robust and long-ranged assembly forces. Together, these developments constitute an important step towards a comprehensive theoretical framework for controlling self-assembly in nonequilibrium environments.

Medicare Coverage and Patient Out-of-Pocket Costs for Cardiovascular-Kidney-Metabolic Medications.

This cross-sectional study evaluates the association between Medicare coverage and patient out-of-pocket costs for cardiovascular-kidney-metabolic medications.

Sensorimotor delays constrain robust locomotion in a 3D kinematic model of fly walking.

Walking animals must maintain stability in the presence of external perturbations, despite significant temporal delays in neural signaling and muscle actuation. Here, we develop a 3D kinematic model with a layered control architecture to investigate how sensorimotor delays constrain robustness of walking behavior in the fruit fly, Drosophila. Motivated by the anatomical architecture of insect locomotor control circuits, our model consists of three component layers: a neural network that generates realistic 3D joint kinematics for each leg, an optimal controller that executes the joint kinematics while accounting for delays, and an inter-leg coordinator. The model generates realistic simulated walking that matches real fly walking kinematics and sustains walking even when subjected to unexpected perturbations, generalizing beyond its training data. However, we found that the model's robustness to perturbations deteriorates when sensorimotor delay parameters exceed the physiological range. These results suggest that fly sensorimotor control circuits operate close to the temporal limit at which they can detect and respond to external perturbations. More broadly, we show how a modular, layered model architecture can be used to investigate physiological constraints on animal behavior.

INHIBITORS OF INORGANIC POLYPHOSPHATE AND NUCLEIC ACIDS ATTENUATE IN VITRO THROMBIN GENERATION IN PLASMA FROM TRAUMA PATIENTS.

ABSTRACT: Background: Inorganic polyphosphate (polyP) is a procoagulant polyanion. We assessed the impact of polyP inhibition on thrombin generation after trauma using the novel polyP antagonists, macromolecular polyanion inhibitor 8 (MPI 8), and universal heparin reversal agent 8 (UHRA-8). Methods: Plasma thrombin generation (calibrated automated thrombogram, CAT), in 56 trauma patients and 39 controls +/- MPI 8 and UHRA-8 (50 µg/mL), was expressed as lag time (LT, minutes), peak height (PH, nM), and time to peak (ttPeak, minutes), with change in LT (ΔLT) and change in ttPeak (ΔttPeak) quantified. Results expressed in median and quartiles [Q1, Q3], Wilcoxon matched-pairs testing, P < 0.05 significant. Results: Trauma patients had greater baseline PH than controls (182.9 [121.0, 255.2]; 120.5 [62.1, 174.8], P < 0.001). MPI 8 treatment prolonged LT and ttPeak in trauma (7.20 [5.88, 8.75]; 6.46 [5.45, 8.93], P = 0.020; 11.28 [8.96, 13.14]; 11.00 [8.95, 12.94], P = 0.029) and controls (7.67 [6.67, 10.50]; 6.33 [5.33, 8.00], P < 0.001; 13.33 [11.67, 15.33]; 11.67 [10.33, 13.33], P < 0.001). UHRA-8 treatment prolonged LT and ttPeak and decreased PH in trauma (9.09 [7.45, 11.33]; 6.46 [5.45, 8.93]; 14.02 [11.78, 17.08]; 11.00 [8.95, 12.94]; 117.4 [74.5, 178.6]; 182.9 [121.0, 255.2]) and controls (9.83 [8.00, 12.33]; 6.33 [5.33, 8.00]; 16.67 [14.33, 20.00]; 11.67 [10.33, 13.33]; 55.3 [30.2, 95.9]; 120.5 [62.1, 174.8]), all P < 0.001. Inhibitor effects were greater for controls (greater ΔLT and ΔttPeak for both inhibitors, P < 0.001). Conclusion: PolyP inhibition attenuates thrombin generation, though to a lesser degree in trauma than in controls, suggesting that polyP contributes to accelerated thrombin generation after trauma.

Primary care usage at the end of life: a retrospective cohort study of cancer patients using linked primary and hospital care data.

PURPOSE: Health service use is most intensive in the final year of a person's life, with 80% of this expenditure occurring in hospital. Close involvement of primary care services has been promoted to enhance quality end-of-life care that is appropriate to the needs of patients. However, the relationship between primary care involvement and patients' use of hospital care is not well described. This study aims to examine primary care use in the last year of life for cancer patients and its relationship to hospital usage. METHODS: Retrospective cohort study in Victoria, Australia, using linked routine care data from primary care, hospital and death certificates. Patients were included who died related to cancer between 2008 and 2017. RESULTS: A total of 758 patients were included, of whom 88% (n = 667) visited primary care during the last 6 months (median 9.1 consultations). In the last month of life, 45% of patients were prescribed opioids, and 3% had imaging requested. Patients who received home visits (13%) or anticipatory medications (15%) had less than half the median bed days in the last 3 months (4 vs 9 days, p < 0.001, 5 vs 10 days, p = 0.001) and 1 month of life (0 vs 2 days, p = 0.002, 0 vs 3 days, p < 0.001), and reduced emergency department presentations (32% vs 46%, p = 0.006, 31% vs 47% p < 0.001) in the final month. CONCLUSION: This study identifies two important primary care processes-home visits and anticipatory medication-associated with reduced hospital usage and intervention at the end of life.

Common and divergent molecular mechanisms of fasting and ketogenic diets.

Intermittent short-term fasting (ISTF) and ketogenic diets (KDs) exert overlapping but not identical effects on cell metabolism, function, and resilience. Whereas health benefits of KD are largely mediated by the ketone bodies (KBs), ISTF engages additional adaptive physiological responses. KDs act mainly through inhibition of histone deacetylases (HDACs), reduction of oxidative stress, improvement of mitochondria efficiency, and control of inflammation. Mechanisms of action of ISTF include stimulation of autophagy, increased insulin and leptin sensitivity, activation of AMP-activated protein kinase (AMPK), inhibition of the mechanistic target of rapamycin (mTOR) pathway, bolstering mitochondrial resilience, and suppression of oxidative stress and inflammation. Frequent switching between ketogenic and nonketogenic states may optimize health by increasing stress resistance, while also enhancing cell plasticity and functionality.

The development and validation of a Multidimensional Perceived Work Ability Scale.

Research on the concept of existing unidimensional Perceived Work Ability scale (PWA) in organizational science has recently increased due to its prediction of important work, individual, and labor force outcomes. To date, PWA has been measured as a unidimensional construct. The present study outlines the need for the multidimensional conceptualization of PWA and its measurement. We describe the development and validation of the Multidimensional Perceived Work Ability Scale (M-PWAS), comprising four dimensions: physical, cognitive, interpersonal, and emotional. In line with Hinkin's (1998) approach to scale validation, we use four samples (total N = 1,152) to establish the M-PWAS as a reliable and valid measure of PWA. Through an iterative item generation and review process, we found evidence for content validity. Furthermore, each subscale demonstrated high internal consistency and factorial validity, and analysis of the PWA nomological network demonstrated evidence for convergent and discriminant validity. Finally, we found that the M-PWAS showed incremental validity over an existing unidimensional PWA measure in the prediction of perceived stress, emotional exhaustion, work engagement, and turnover. We discuss implications for theory, research, and workplace interventions. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Factors influencing patient selection of orthopaedic surgeons for total hip (THA) and total knee arthroplasty (TKA).

INTRODUCTION: The importance of identifying how patients choose their healthcare providers has grown with the prevalence of consumer-centric health insurance plans. There is currently a lack of studies exploring the factors associated with how patients select their hip and knee joint arthroplasty surgeons. The purpose of this study was to determine how patients find their arthroplasty providers and the relative importance of various arthroplasty surgeon characteristics. METHODS: An electronic mail survey was sent to 3522 patients who had visited our institution for an arthroplasty surgeon office visit between August 2022 and January 2023. The survey consisted of multiple-choice questions, which aimed to inquire about the patients' referral sources for their current arthroplasty surgeon. In addition, patients were requested to rate the significance of 22 surgeon-related factors, on a scale of 1 (Not Important At All) to 5 (Very Important), in choosing their arthroplasty surgeon. RESULTS: Of the 3522 patients that received the survey, 538 patients responded (15.3%). The most common referral sources were physician referral (50.2%), family/friend referral (27.7%), and self-guided research (24.5%). Of those that were referred by a physician, 54.4% of respondents were referred by another orthopaedic provider. Patients rated board certification (4.72 ± 0.65), in-network insurance status (4.66 ± 0.71), fellowship training (4.50 ± 0.81), bedside manner/personality (4.32 ± 0.86), and facility appearance (4.26 ± 0.81) as the five most important factors in picking an arthroplasty surgeon. Television (1.42 ± 0.83), print (1.50 ± 0.88), and online (1.58 ± 0.93) advertisements, along with social media presence (1.83 ± 1.08), and practice group size (2.97 ± 1.13) were rated as the five least important factors. CONCLUSION: Patients are most likely to select an arthroplasty surgeon based on referral from other physicians, namely orthopedic surgeons, in addition to board certification status, in-network insurance, and fellowship training. Overall, these findings highlight the importance of physician credentials and reputation within the orthopaedic community in order to attract and retain patients.

Preclinical validation of NeoWarm, a low-cost infant warmer and carrier device, to ameliorate induced hypothermia in newborn piglets as models for human neonates.

Introduction: Approximately 1.5 million neonatal deaths occur among premature and small (low birthweight or small-for gestational age) neonates annually, with a disproportionate amount of this mortality occurring in low- and middle-income countries (LMICs). Hypothermia, the inability of newborns to regulate their body temperature, is common among prematurely born and small babies, and often underlies high rates of mortality in this population. In high-resource settings, incubators and radiant warmers are the gold standard for hypothermia, but this equipment is often scarce in LMICs. Kangaroo Mother Care/Skin-to-skin care (KMC/STS) is an evidence-based intervention that has been targeted for scale-up among premature and small neonates. However, KMC/STS requires hours of daily contact between a neonate and an able adult caregiver, leaving little time for the caregiver to care for themselves. To address this, we created a novel self-warming biomedical device, NeoWarm, to augment KMC/STS. The present study aimed to validate the safety and efficacy of NeoWarm. Methods: Sixteen, 0-to-5-day-old piglets were used as an animal model due to similarities in their thermoregulatory capabilities, circulatory systems, and approximate skin composition to human neonates. The piglets were placed in an engineered cooling box to drop their core temperature below 36.5°C, the World Health Organizations definition of hypothermia for human neonates. The piglets were then warmed in NeoWarm (n = 6) or placed in the ambient 17.8°C ± 0.6°C lab environment (n = 5) as a control to assess the efficacy of NeoWarm in regulating their core body temperature. Results: All 6 piglets placed in NeoWarm recovered from hypothermia, while none of the 5 piglets in the ambient environment recovered. The piglets warmed in NeoWarm reached a significantly higher core body temperature (39.2°C ± 0.4°C, n = 6) than the piglets that were warmed in the ambient environment (37.9°C ± 0.4°C, n = 5) (p < 0.001). No piglet in the NeoWarm group suffered signs of burns or skin abrasions. Discussion: Our results in this pilot study indicate that NeoWarm can safely and effectively warm hypothermic piglets to a normal core body temperature and, with additional validation, shows promise for potential use among human premature and small neonates.

Photonic bandgap microcombs at 1064 nm.

Microresonator frequency combs and their design versatility have revolutionized research areas from data communication to exoplanet searches. While microcombs in the 1550 nm band are well documented, there is interest in using microcombs in other bands. Here, we demonstrate the formation and spectral control of normal-dispersion dark soliton microcombs at 1064 nm. We generate 200 GHz repetition rate microcombs by inducing a photonic bandgap of the microresonator mode for the pump laser with a photonic crystal. We perform the experiments with normal-dispersion microresonators made from Ta2O5 and explore unique soliton pulse shapes and operating behaviors. By adjusting the resonator dispersion through its nanostructured geometry, we demonstrate control over the spectral bandwidth of these combs, and we employ numerical modeling to understand their existence range. Our results highlight how photonic design enables microcomb spectra tailoring across wide wavelength ranges, offering potential in bioimaging, spectroscopy, and photonic-atomic quantum technologies.

Comparisons between dual-energy X-ray absorptiometry and bioimpedance devices for appendicular lean mass and muscle quality in Hispanic adults.

The purpose of this study was to compare single- and multi-frequency bioimpedance (BIA) devices against dual-energy X-ray absorptiometry (DXA) for appendicular lean mass (ALM) and muscle quality index (MQI) metrics in Hispanic adults. One hundred thirty-one Hispanic adults (18-55 years) participated in this study. ALM was measured with single-frequency bioimpedance analysis (SFBIA), multi-frequency bioimpedance analysis (MFBIA) and DXA. ALMTOTAL (left arm + right arm + left leg + right leg) and ALMARMS (left arm + right arm) were computed for all three devices. Handgrip strength (HGS) was measured using a dynamometer. The average HGS was used for all MQI models (highest left hand + highest right hand)/2. MQIARMS was defined as the ratio between HGS and ALMARMS. MQITOTAL was established as the ratio between HGS and ALMTOTAL. SFBIA and MFBIA had strong correlations with DXA for all ALM and MQI metrics (Lin's concordance correlation coefficient values ranged from 0·86 (MQIMFBIA-ARMS) to 0·97 (Arms LMSFBIA); all P < 0·001). Equivalence testing varied between methods (e.g. SFBIA v. DXA) when examining the different metrics (i.e. ALMTOTAL, ALMARMS, MQITOTAL and MQIARMS). MQIARMS was the only metric that did not differ from the line of identity and had no proportional bias when comparing all the devices against each other. The current study findings demonstrate good overall agreement between SFBIA, MFBIA and DXA for ALMTOTAL and ALMARMS in a Hispanic population. However, SFBIA and MFBIA have better agreement with DXA when used to compute MQIARMS than MQITOTAL.

Glycoprotein Matrix Zinc Exhibits Improved Absorption: A Randomized Crossover Trial.

Biotransformation of minerals via glycosylation by microorganisms such as yeast and/or probiotics yields nutrients bound to a food matrix, resulting in increased bioavailability. The purpose of this study was to compare the effects of glycoprotein matrix-bound zinc (GPM) on absorption compared to inorganic zinc oxide. Sixteen participants ingested 11 mg of zinc as either GPM™ Soy-Free Zinc (GPM, Ashland, Kearny, NJ, USA) or zinc oxide (USP). Blood samples were taken at 0 (i.e., baseline), 30, 60, 90, 120, 180, 240, 300, 360, 420, and 480 min post-ingestion. GPM zinc concentrations were significantly higher at 120 min (p = 0.02; 12.4 ± 5.1 mcg/dL), 180 min (p = 0.002; 16.8 ± 5.1 mcg/dL), and 240 min (p = 0.007; 14.6 ± 5.1 mcg/dL) in comparison to USP zinc oxide. In addition, GPM zinc significantly increased iAUC by 40% (5840 ± 2684 vs. 4183 ± 1132 mcg/dL * 480 min, p = 0.02), and Cmax values were 10% higher in GPM compared to USP (148 ± 21 mcg/dL vs. 135 ± 17.5 mcg/dL, p = 0.08). Tmax was 12% slower in GPM compared to USP (112.5 ± 38.7 min vs. 127.5 ± 43.1 min); however, differences in Tmax failed to reach statistical significance (p = 0.28). Zinc bound to a glycoprotein matrix significantly increased absorption compared to zinc oxide.

Assessment of minimum target dose as a predictor of local failure after spine SBRT.

OBJECTIVES: Metastasis-directed stereotactic body radiation therapy (SBRT) has demonstrated robust clinical benefits in carefully selected patients, improving local control and even overall survival (OS). We assess a large database to determine clinical and dosimetric predictors of local failure after spine SBRT. METHODS: Spine SBRT treatments with imaging follow-up were identified. Patients were treated with a simultaneous integrated boost technique using 1 or 3 fractions, delivering 20-24 Gy in 1 fraction to the gross tumor volume (GTV) and 16 Gy to the low dose volume (or 27-36 Gy and 21-24 Gy for 3 fraction treatments). Exclusions included: lack of imaging follow-up, proton therapy, and benign primary histologies. RESULTS: 522 eligible spine SBRT treatments (68 % single fraction) were identified in 377 unique patients. Patients had a median OS of 43.7 months (95 % confidence interval: 34.3-54.4). The cumulative incidence of local failure was 10.5 % (7.4-13.4) at 1 year and 16.3 % (12.6-19.9) at 2 years. Local control was maximized at 15.3 Gy minimum dose for single-fraction treatment (HR = 0.31, 95 % CI: 0.17 - 0.56, p < 0.0001) and confirmed via multivariable analyses. Cumulative incidence of local failure was 6.1 % (2.6-9.4) vs. 14.2 % (8.3-19.8) at 1 year using this cut-off, with comparable findings for minimum 14 Gy. Additionally, epidural and soft tissue involvement were predictive of local failure (HR = 1.77 and 2.30). CONCLUSIONS: Spine SBRT offers favorable local control; however, minimum dose to the GTV has a strong association with local control. Achieving GTV minimum dose of 14-15.3 Gy with single fraction SBRT is recommended whenever possible.

Skeletal muscle estimation: A review of techniques and their applications.

Quantifying skeletal muscle size is necessary to identify those at risk for conditions that increase frailty, morbidity, and mortality, as well as decrease quality of life. Although muscle strength, muscle quality, and physical performance have been suggested as important assessments in the screening, prevention, and management of sarcopenic and cachexic individuals, skeletal muscle size is still a critical objective marker. Several techniques exist for estimating skeletal muscle size; however, each technique presents with unique characteristics regarding simplicity/complexity, cost, radiation dose, accessibility, and portability that are important factors for assessors to consider before applying these modalities in practice. This narrative review presents a discussion centred on the theory and applications of current non-invasive techniques for estimating skeletal muscle size in diverse populations. Common instruments for skeletal muscle assessment include imaging techniques such as computed tomography, magnetic resonance imaging, peripheral quantitative computed tomography, dual-energy X-ray absorptiometry, and Brightness-mode ultrasound, and non-imaging techniques like bioelectrical impedance analysis and anthropometry. Skeletal muscle size can be acquired from these methods using whole-body and/or regional assessments, as well as prediction equations. Notable concerns when conducting assessments include the absence of standardised image acquisition/processing protocols and the variation in cut-off thresholds used to define low skeletal muscle size by clinicians and researchers, which could affect the accuracy and prevalence of diagnoses. Given the importance of evaluating skeletal muscle size, it is imperative practitioners are informed of each technique and their respective strengths and weaknesses.

The effect of mephedrone on human neuroblastoma and astrocytoma cells.

Mephedrone is an illegal drug that is used recreationally. Few studies have been conducted to investigate the mechanisms by which mephedrone is harming cells. In this research, we investigated the effect of mephedrone using toxicology coupled with LC-MS/MS based metabolomics in the two CNS derived cell lines. Methods of assessment such as neutral red (NR) assay, dimethylthiazolyl diphenyltetrazolium bromide (MTT), lactose dehydrogenase (LDH) measurement, and morphology were performed to identify the effect on cell viability and to identify the best concentration to be used in a metabolomics study. A concentration of 100 µM of mephedrone was used in the metabolomic experiment because at this concentration mephedrone had induced several intracellular changes. Although there no clear indicators of cellular damage caused by mephedrone. In astrocytes there was a clear indication that cell membrane function might be impaired by depletion of ether lipids.

Controlled Stiffness of Direct-Write, Near-Field Electrospun Gelatin Fibers Generates Differences in Tenocyte Morphology and Gene Expression.

Tendinopathy is a leading cause of mobility issues. Currently, the cell-matrix interactions involved in the development of tendinopathy are not fully understood. In vitro tendon models provide a unique tool for addressing this knowledge gap as they permit fine control over biochemical, micromechanical, and structural aspects of the local environment to explore cell-matrix interactions. In this study, direct-write, near-field electrospinning of gelatin solution was implemented to fabricate micron-scale fibrous scaffolds that mimic native collagen fiber size and orientation. The stiffness of these fibrous scaffolds was found to be controllable between 1 MPa and 8 MPa using different crosslinking methods (EDC, DHT, DHT+EDC) or through altering the duration of crosslinking with EDC (1 h to 24 h). EDC crosslinking provided the greatest fiber stability, surviving up to 3 weeks in vitro. Differences in stiffness resulted in phenotypic changes for equine tenocytes with low stiffness fibers (∼1 MPa) promoting an elongated nuclear aspect ratio while those on high stiffness fibers (∼8 MPa) were rounded. High stiffness fibers resulted in the upregulation of matrix metalloproteinase (MMPs) and proteoglycans (possible indicators for tendinopathy) relative to low stiffness fibers. These results demonstrate the feasibility of direct-written gelatin scaffolds as tendon in vitro models and provide evidence that matrix mechanical properties may be crucial factors in cell-matrix interactions during tendinopathy formation.