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Updated: Jun 25, 2026
Characteristics of Precipitation-formed Polyethylene Glycol Microgels Are Controlled by Molecular Weight of Reactants
Published on: December 23, 2013
Polyethylene glycol addition does not improve exogenous surfactant function in an experimental model of meconium
Joao Cesar Lyra1, Renata Suman Mascaretti, Alexander Roberto Precioso
1Department of Pediatrics, São Paulo State University, Rubiao Junior, Campus Botucatu, Botucatu, Brazil. jc.lyra@uol.com.br
Abstract:
Meconium (MEC) is a potent inactivator of pulmonary surfactant. The authors studied the effects of polyethylene glycol addition to the exogenous surfactant over the lung mechanics and volumes. Human meconium was administrated to newborn rabbits. Animals were ventilated for 20 minutes and dynamic compliance, ventilatory pressure, and tidal volume were recorded. Animals were randomized into 3 study groups: MEC group (without surfactant therapy); S100 group (100 mg/kg surfactant); and PEG group (100 mg/kg porcine surfactant plus 5% PEG). After ventilation, a pulmonary pressure-volume curve was built. Histological analysis was carried out to calculate the mean alveolar size (Lm) and the distortion index (DI). Both groups treated with surfactant showed higher values of dynamic pulmonary compliance and lower ventilatory pressure, compared with the MEC group (P < .05). S100 group had a larger maximum lung volume, V(30), compared with the MEC group (P < .05). Lm and DI values were smaller in the groups treated with surfactant than in the MEC group (P < .05). No differences were observed between the S100 and PEG groups. Animals treated with surfactant showed significant improvement in pulmonary function as compared to nontreated animals. PEG added to exogenous surfactant did not improve lung mechanics or volumes.
Insights
Exogenous surfactant improves lung function in meconium-exposed rabbits, but adding polyethylene glycol (PEG) offers no additional benefit. Surfactant therapy is crucial for mitigating meconium
Area of Science:
- Neonatal Physiology
- Pulmonary Medicine
- Biomaterials Science
Background:
- Meconium aspiration syndrome (MAS) is a severe neonatal condition.
- Meconium inactivates pulmonary surfactant, impairing lung function.
- Exogenous surfactant therapy is a potential treatment for MAS.
Purpose of the Study:
- To investigate the efficacy of polyethylene glycol (PEG) addition to exogenous surfactant in improving lung mechanics and volumes in a meconium-induced lung injury model.
- To assess the impact of PEGylated surfactant on pulmonary function and histology.
Main Methods:
- Newborn rabbits were exposed to meconium and randomized into three groups: meconium only, surfactant therapy, and PEGylated surfactant therapy.
- Lung mechanics (dynamic compliance, ventilatory pressure, tidal volume) were measured during ventilation.
- Pulmonary pressure-volume curves and histological analyses (mean alveolar size, distortion index) were performed.
Main Results:
- Surfactant therapy significantly improved dynamic pulmonary compliance and reduced ventilatory pressure compared to the meconium-only group.
- Surfactant treatment led to improved lung volumes and reduced alveolar distortion.
- No significant differences in lung mechanics, volumes, or histology were observed between the standard surfactant and PEGylated surfactant groups.
Conclusions:
- Exogenous surfactant therapy effectively improves lung function and histology in a meconium-induced lung injury model.
- The addition of polyethylene glycol (PEG) to exogenous surfactant does not provide additional benefits in this model.
- Further research may explore alternative PEGylation strategies or other adjunct therapies for MAS.
