Despite the success of current therapies for acute myocardial infarction (MI), many patients still develop adverse cardiac remodeling and heart failure. With the growing prevalence of heart failure, a new therapy is needed that can prevent remodeling and support tissue repair. Herein, we report on injectable recombinant human collagen type I (rHCI) and type III (rHCIII) matrices for treating MI. Injecting rHCI or rHCIII matrices in mice during the late proliferative phase post-MI restores the myocardium’s mechanical properties and reduces scar size, but only the rHCI matrix maintains remote wall thickness and prevents heart enlargement. rHCI treatment increases cardiomyocyte and capillary numbers in the border zone and the presence of pro-wound healing macrophages in the ischemic area, while reducing the overall recruitment of bone marrow monocytes. Our findings show functional recovery post-MI using rHCI by promoting a healing environment, cardiomyocyte survival, and less pathological remodeling of the myocardium.

The effects of fetal cocaine exposure on newborn cry characteristics were studied in 80 cocaine-exposed and 80 control infants. The groups were stratified to be similar on maternal demographic characteristics and maternal use of other illegal substances and alcohol during pregnancy. The hypothesis was that excitable cry characteristics were related to the direct effects of cocaine, while depressed cry characteristics were related to the indirect effects of cocaine secondary to low birthweight. Structural equation modeling (EQS) showed direct effects of cocaine on cries with a longer duration, higher fundamental frequency, and a higher and more variable first formant frequency. Indirect effects of cocaine secondary to low birthweight resulted in cries with a longer latency, fewer utterances, lower amplitude, and more dysphonation. Cocaine-exposed infants had a lower birthweight, shorter length, and smaller head circumference than the unexposed controls. Findings were consistent with the notion that 2 neurobehavioral syndromes, excitable and depressed, can be described in cocaine-exposed infants, and that these 2 syndromes are due, respectively, to direct neurotoxic effects and indirect effects secondary to intrauterine growth retardation.

Sprayable formulations of AgNPs were prepared by exchanging citrate capping agents with LL37-SH peptides. The AgNP@LL37 material was then combined with type I collagen to form a stable film once sprayed. The AgNP@LL37 spray prevented Pseudomonas aeruginosa (P. aeruginosa) proliferation and eradicated a P. aeruginosa biofilm, while being non-toxic for human skin fibroblasts embedded within 3D artificial skin constructs. Finally, no silver infiltration was observed after spraying on a full-thickness skin wound in a mouse model.

Nanomaterials have attracted the interest of tissue engineers for the last two decades. Their unique properties make them promising for de novo fabrication of bio-inspired hybrid/composite materials with improved regenerative properties, including, for example, the capacity for electric conductivity and the provision of antimicrobial properties. However, to this day, the use of such materials in medical applications is rather limited and most of the studies have only reached the archetypical proof-of-concept stage. Herein, we present a review on the use of nanomaterials in tissue engineering for regenerative therapies of heart, skin, eye, skeletal muscle, and nervous system. The advantages and limitations of nano-engineering materials are presented in this review alongside with the future challenges and milestones nanotechnology must overcome to make an impact in biomedical applications.

Objective To evaluate the relationship of maternal antenatal magnesium sulfate (MgSO4) with neonatal cranial ultrasound abnormalities and cerebral palsy (CP). Study design In a randomized trial of MgSO4 or placebo in women at high risk of preterm delivery, up to three cranial ultrasound were obtained in the neonatal period. Images were reviewed by at least two pediatric radiologists masked to treatment and other clinical conditions. Diagnoses were predefined for intraventricular hemorrhage (IVH), periventricular leukomalacia (PVL), intracerebral echolucency or echodensity, and ventriculomegaly. CP was diagnosed at two years by standardized neurological examination. Results Intraventricular hemorrhage, PVL, intracerebral echolucency or echodensity, and ventriculomegaly were all strongly associated with an increased risk of CP. MgSO4 administration did not affect the risk of cranial ultrasound abnormality observed at 35 weeks post-menstrual age or later. However, for the 82% of infants born at <32 weeks gestation, MgSO4 was associated with a reduction in risk of echolucency or echodensity. The reduction in risk for echolucency explained 21% of the effect of MgSO4 on CP (p=0.04), and for echodensity explained 20% of the effect (p=0.02). Conclusions MgSO4 given prior to preterm delivery was associated with decreased risk of developing echodensities and echolucencies at <32 weeks gestation. However, this effect can only partially explain the effect of MgSO4 on CP at two years of age.