RESUMEN
Knee meniscus tears are one of the most common musculoskeletal injuries. While meniscus replacements using allografts or biomaterial-based scaffolds are available, these treatments rarely result in integrated, functional tissue. Understanding mechanotransducive signaling cues that promote a meniscal cell regenerative phenotype is critical to developing therapies that promote tissue regeneration rather than fibrosis after injury. The purpose of this study was to develop a hyaluronic acid (HA) hydrogel system with tunable crosslinked network properties by modulating the degree of substitution (DoS) of reactive-ene groups to investigate mechanotransducive cues received by meniscal fibrochondrocytes (MFCs) from their microenvironment. A thiol-ene step-growth polymerization crosslinking mechanism was employed using pentenoate-functionalized hyaluronic acid (PHA) and dithiothreitol to achieve tunability of the chemical crosslinks and resulting network properties. Increased crosslink density, reduced swelling, and increased compressive modulus (60-1020 kPa) were observed with increasing DoS. Osmotic deswelling effects were apparent in PBS and DMEM+ compared to water; swelling ratios and compressive moduli were decreased in the ionic buffers. Frequency sweep studies showed storage and loss moduli of hydrogels at 1 Hz approach reported meniscus values and showed increasing viscous response with increasing DoS. The degradation rate increased with decreasing DoS. Lastly, modulating PHA hydrogel surface modulus resulted in control of MFC morphology, suggesting relatively soft hydrogels (E = 60 ± 35 kPa) promote more inner meniscus phenotype compared to rigid hydrogels (E = 610 ± 66 kPa). Overall, these results highlight the use of -ene DoS modulation in PHA hydrogels to tune crosslink density and physical properties to understand mechanotransduction mechanisms required to promote meniscus regeneration.
Asunto(s)
Hidrogeles , Menisco , Hidrogeles/farmacología , Hidrogeles/química , Ácido Hialurónico/farmacología , Ácido Hialurónico/química , Mecanotransducción Celular , Materiales Biocompatibles/químicaRESUMEN
Obesity rates among children are rapidly rising internationally and have been linked to noncommunicable diseases in adulthood. Individual preventive strategies have not effectively reduced global obesity rates, leading to a gap in clinical services regarding the development of early perinatal interventions. The objective of this scoping review is to explore the relationship between maternal BMI and breastfeeding behaviors on child growth trajectories to determine their relevance in developing interventions aimed at preventing childhood obesity.The scoping review was guided and informed by the Arksey and O'Malley (2005) framework. A systematic search was performed in four databases. Studies included in the final review were collated and sorted into relevant themes. A systematic search yielded a total of 5831 records (MEDLINE: 1242, EMBASE: 2629, CINAHL: 820, PubMed: 1140). Results without duplicates (n = 4190) were screened based on relevancy of which 197 relevant-full-text articles were retrieved and assessed for eligibility resulting in 14 studies meeting the inclusion criteria. Data were extracted and charted for the studies and six themes were identified: (1) healthy behaviors, lifestyle, and social economic status; (2) parental anthropometrics and perinatal weight status; (3) genetics, epigenetics, and fetal programming; (4) early infant feeding; (5) infant growth trajectories; and (6) targeted prevention and interventions. Early life risk factors for child obesity are multifactorial and potentially modifiable. Several at-risk groups were identified who would benefit from early preventative interventions targeting the importance of healthy weight gain, exclusive breastfeeding to 6 months, and healthy lifestyle behaviors.