Publications by authors named "Kirill V Larin"

Purpose: To assess the safety of acoustic radiation force optical coherence elastography in the crystalline lens in situ.

Methods: Acoustic radiation force (ARF) produced by an immersion single-element ultrasound transducer (nominal frequency = 3.5 MHz) was characterized using a needle hydrophone and used for optical coherence elastography (OCE) of the crystalline lens.

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Significance: The skin's mechanical properties are tightly regulated. Various pathologies can affect skin stiffness, and understanding these changes is a focus in tissue engineering. skin scaffolds are a robust platform for evaluating the effects of various genetic and molecular interactions on the skin.

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During the first month of pregnancy, the brain and spinal cord are formed through a process called neurulation. However, this process can be altered by low serum levels of folic acid, environmental factors, or genetic predispositions. In 2018, a surveillance study in Botswana, a country with a high incidence of human immunodeficiency virus (HIV) and lacking mandatory food folate fortification programs, found that newborns whose mothers were taking dolutegravir (DTG) during the first trimester of pregnancy had an increased risk of neural tube defects (NTDs).

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Acute alcohol ingestion has been found to impact visual functions, including eye movement, but its effects on corneal biomechanical properties remain unclear. This study aimed to investigate the influence of acute alcohol consumption on corneal biomechanical properties using optical coherence elastography (OCE). An air-coupled ultrasound transducer induced elastic waves in mice corneas in vivo, and a high-resolution phase-sensitive optical coherence tomography (OCT) system tracked the mechanical waves to quantify the elastic wave speed.

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Article Synopsis
  • Progress in nanostructured self-assembling systems has led to the creation of various nanoscale shapes, but controlling structures across different lengths remains a challenge.
  • A new extrusion-based method was developed to produce aligned, nanofibrous hydrogels using self-assembling peptides, enhancing their strength when adjusting buffer concentrations during assembly.
  • These hydrogels can mimic extracellular matrices to guide cell behavior, but the relationship between matrix alignment and cell alignment is complex, highlighting the importance of understanding how cells interact with nanofibrous structures.
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Neurulation is a highly synchronized biomechanical process leading to the formation of the brain and spinal cord, and its failure leads to neural tube defects (NTDs). Although we are rapidly learning the genetic mechanisms underlying NTDs, the biomechanical aspects are largely unknown. To understand the correlation between NTDs and tissue stiffness during neural tube closure (NTC), we imaged an NTD murine model using optical coherence tomography (OCT), Brillouin microscopy and confocal fluorescence microscopy.

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Noninvasive monitoring of cardiac development can potentially prevent cardiac anomalies in adulthood. Mouse models provide unique opportunities to study cardiac development and disease in mammals. However, high-resolution noninvasive functional analyses of murine embryonic cardiac models are challenging because of the small size and fast volumetric motion of the embryonic heart, which is deeply embedded inside the uterus.

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Background: The brain and spinal cord formation is initiated in the earliest stages of mammalian pregnancy in a highly organized process known as neurulation. Environmental or genetic interferences can impair neurulation, resulting in clinically significant birth defects known collectively as neural tube defects. The Fuz gene encodes a subunit of the CPLANE complex, a macromolecular planar polarity effector required for ciliogenesis.

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Fibrous proteins that comprise the extracellular matrix (ECM) guide cellular growth and tissue organization. A lack of synthetic strategies able to generate aligned, ECM-mimetic biomaterials has hampered bottom-up tissue engineering of anisotropic tissues and led to a limited understanding of cell-matrix interactions. Here, we present a facile extrusion-based fabrication method to produce anisotropic, nanofibrous hydrogels using self-assembling peptides.

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Significance: The biomechanical impact of refractive surgery has long been an area of investigation. Changes to the cornea structure cause alterations to its mechanical integrity, but few studies have examined its specific mechanical impact.

Aim: To quantify how the biomechanical properties of the cornea are altered by laser assisted keratomileusis (LASIK) using optical coherence elastography (OCE) in porcine corneas.

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Many tissues are composed of layered structures, and a better understanding of the changes in the layered tissue biomechanics can enable advanced guidance and monitoring of therapy. The advent of elastography using longitudinally propagating shear waves (LSWs) has created the prospect of a high-resolution assessment of depth-dependent tissue elasticity. Laser activation of liquid-to-gas phase transition of dye-loaded perfluorocarbon (PFC) nanodroplets (a.

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Circulating miRNAs the in blood are promising biomarkers for predicting pregnancy complications and adverse birth outcomes. Previous work identified 11 gestationally elevated maternal circulating miRNAs (HEamiRNAs) that predicted infant growth deficits following prenatal alcohol exposure and regulated epithelial-mesenchymal transition in the placenta. Here we show that a single intravascular administration of pooled murine-conserved HEamiRNAs to pregnant mice on gestational day 10 (GD10) attenuates umbilical cord blood flow during gestation, explaining the observed intrauterine growth restriction (IUGR), specifically decreased fetal weight, and morphometric indices of cranial growth.

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Significance: Quantifying the biomechanical properties of the whole eye globe can provide a comprehensive understanding of the interactions among interconnected ocular components during dynamic physiological processes. By doing so, clinicians and researchers can gain valuable insights into the mechanisms underlying ocular diseases, such as glaucoma, and design interventions tailored to each patient's unique needs.

Aim: The aim of this study was to evaluate the feasibility and effectiveness of a multifocal acoustic radiation force (ARF) based reverberant optical coherence elastography (RevOCE) technique for quantifying shear wave speeds in different ocular components simultaneously.

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Unlabelled: The formation of the brain and spinal cord is initiated in the earliest stages of mammalian pregnancy in a highly organized process known as neurulation. Convergent and extension movements transforms a flat sheet of ectodermal cells into a narrow and elongated line of neuroepithelia, while a major source of Sonic Hedgehog signaling from the notochord induces the overlying neuroepithelial cells to form two apposed neural folds. Afterward, neural tube closure occurs by synchronized coordination of the surface ectoderm and adjacent neuroepithelial walls at specific axial regions known as neuropores.

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Significance: Maternal exposure to drugs during pregnancy is known to have detrimental effects on the fetus. Alcohol (ethanol) and nicotine are two of the most commonly co-abused substances during pregnancy, and prenatal poly-drug exposure is common due, in part, to the prevalence of unplanned pregnancies. The second trimester is a critical period for fetal neurogenesis and angiogenesis.

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In this study, we introduce a multifocal acoustic radiation force source that combines an ultrasound transducer and a 3D-printed acoustic lens for application in reverberant optical coherence elastography (Rev-OCE). An array of plano-concave acoustic lenses, each with an 11.8 mm aperture diameter, were used to spatially distribute the acoustic energy generated by a 1 MHz planar ultrasound transducer, producing multiple focal spots on a target plane.

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The crystalline lens is a transparent, biconvex structure that has its curvature and refractive power modulated to focus light onto the retina. This intrinsic morphological adjustment of the lens to fulfill changing visual demands is achieved by the coordinated interaction between the lens and its suspension system, which includes the lens capsule. Thus, characterizing the influence of the lens capsule on the whole lens's biomechanical properties is important for understanding the physiological process of accommodation and early diagnosis and treatment of lenticular diseases.

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Alcohol and marijuana are two of the most consumed psychoactive substances by pregnant people, and independently, both substances have been associated with lifelong impacts on fetal neurodevelopment. Importantly, individuals of child-bearing age are increasingly engaging in simultaneous alcohol and cannabinoid (SAC) use, which amplifies each drug's pharmacodynamic effects and increases craving for both substances. However, to date, investigations of prenatal polysubstance use are notably limited in both human and non-human populations.

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Purpose: Hyaluronan (HA) is a major constituent of the extracellular matrix (ECM) that has high viscosity and is essential for maintaining tissue hydration. In the cornea, HA is enriched in the limbal region and is a key component of the limbal epithelial stem cell niche. HA is upregulated after injury participating in the formation of the provisional matrix, and has a key role in regulating the wound healing process.

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Purpose: Collagen XII plays a role in regulating the structure and mechanical properties of the cornea. In this work, several optical elastography techniques were used to investigate the effect of collagen XII deficiency on the stiffness of the murine cornea.

Methods: A three-prong optical elastography approach was used to investigate the mechanical properties of the cornea.

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The localized application of the riboflavin/UV-A collagen cross-linking (UV-CXL) corneal treatment has been proposed to concentrate the stiffening process only in the compromised regions of the cornea by limiting the epithelium removal and irradiation area. However, current clinical screening devices dedicated to measuring corneal biomechanics cannot provide maps nor spatial-dependent changes of elasticity in corneas when treated locally with UV-CXL. In this study, we leverage our previously reported confocal air-coupled ultrasonic optical coherence elastography (ACUS-OCE) probe to study local changes of corneal elasticity in three cases: untreated, half-CXL-treated, and full-CXL-treated rabbit corneas (n = 8).

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We present a novel optical coherence elastography (OCE) method to characterize mechanical hysteresis of soft tissues based on transient (milliseconds), low-pressure (<20 Pa) non-contact microliter air-pulse stimulation and micrometer-scale sample displacements. The energy dissipation rate (sample hysteresis) was quantified for soft-tissue phantoms (0.8% to 2.

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The biomechanical properties of the cornea have a profound influence on the health, structural integrity, and function of the eye. Understanding these properties may be critical for diagnosis and identifying disease pathogenesis. This work demonstrates how two different elastography techniques can be combined for a multimodal approach to measuring corneal biomechanical properties.

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Background: Prenatal alcohol exposure (PAE) has been shown to alter fetal blood flow in utero and is also associated with placental insufficiency and intrauterine growth restriction (IUGR), suggesting an underlying connection between perturbed circulation and pregnancy outcomes.

Methods: Timed-pregnant C57/BL6NHsd mice, bred in-house, were exposed by gavage on gestational day 10 (GD10) to ethanol (3 g/kg) or purified water, as a control. Pulse-wave Doppler ultrasound measurements for umbilical arteries and ascending aorta were obtained post-gavage (GD12, GD14, GD18) on 2 fetuses/litter.

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