ASK anyone – except, perhaps, the proud parents – and they’ll tell you a baby’s debut into the world is hardly a pretty sight. Coated in all sorts of body fluids and a white, cheesy paste called vernix, a baby’s momentous first seconds in the world are, well, a little yucky.
But Marty Visscher, executive director of the Skin Sciences Institute of Cincinnati Children’s Hospital Medical Center in Ohio, reckons babies come into the world coated in liquid gold. The vernix that midwives wipe off before they hand the new mother her rosy-skinned bundle of joy is probably the best skin cream the baby will ever have. It has not only protected his or her skin from constant contact with water; it has kept it hydrated, its pH balanced, and may even have primed it against infection and damage in preparation for birth.
“If you take some and rub it in your skin, the feel of it is very much like skin. It doesn’t have the sticky, greasy feel of moisturisers,” says Visscher, who has done the test herself. Now she and her colleagues are hoping to copy nature’s design and develop a synthetic version, which they reckon could help premature babies whose skin has not fully formed. Vernix might also yield the winning formula for new diaper rash creams and medicated lotions for people with skin problems such as eczema and psoriasis. Perhaps even the ultimate moisturiser.
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For more than 10 years, the Cincinnati team has been trying to figure out the composition of vernix and how it interacts with skin. What they and others have found dispels the notion that vernix is merely fatty gunk with little in the way of structure or special properties.
For a start, it has a unique composition that is 80 per cent water, 10 per cent lipids and 10 per cent protein. That’s a lot of water compared with baby ointments. For example, a study published in 2000 by a team led by Steven Hoath, medical director of the Cincinnati institute, showed that ointments commonly used for babies such as petroleum jelly, Eucerin and Aquaphor, contain between 0 and 17 per cent water.
But Hoath’s team also uncovered the real secret of vernix’s properties: how it is able to retain so much water. Most of it is enclosed inside specially adapted skin cells called fetal corneocytes. In unpublished experiments, Visscher’s team exposed corneocytes to varying levels of humidity and found they soaked up water when the humidity was high and released it when the humidity was low. Hoath likes to think of the baby’s vernix as a smart material that carefully manages the condition of its developing skin.
The unique attributes of vernix do not end there. Hoath’s team has found that it also contains high levels of vitamin E, a potent antioxidant. They suggest this might help a newborn’s skin cope with stresses such as oxygen, pollutants and UV light. Some studies suggest that vernix is also an antimicrobial barrier, because it contains proteins that stick to bacteria, viruses and fungi.
Findings are also trickling in that hint at the role vernix might play during the fetus’s development. “There is some very complex biology going on before the baby is born that involves vernix in a central way,” says Hoath. When the fetus is between 25 and 26 weeks into gestation (38 weeks is considered full term), the skin’s sebaceous glands start to produce vernix, which oozes out through the hair follicles. It is also around this time that the final layer of the skin, called the stratum corneum, forms. The timing is key, because this top layer of skin needs a dry environment to finish developing. Vernix may provide it by forming a protective barrier on the baby’s immature skin that drives water away.
But what about those premature babies who haven’t even had the chance to produce vernix? Thanks to advances in neonatal intensive care, babies born as early as 23 weeks can now survive (see Graph). But in babies that are premature, vernix has not had time to appear, so they lack their top skin layers. This poses an enormous challenge for doctors. The skin they do have is so fragile that even placing surgical tape on it may cause injury, says Christoph Bührer, a neonatologist at Charité Medical Centre in Berlin, Germany. The skin they do have is translucent, looks almost jelly-like, and feels rather like the skin of a frog, Bührer says. A baby born with an immature skin surface has problems controlling body temperature and protecting against water loss. And because microbes can penetrate this thin, vulnerable skin, infection is a common cause of death in very premature babies. “[Premature] babies are getting smaller each year,” Bührer says, “and the limiting organ is the skin.”
Ointments such as petroleum jelly or Aquaphor can help protect babies with such immature skin. But it’s not ideal, Bührer says, and developing a vernix-like cream could make a big difference. “Whatever improves skin integrity will help improve babies’ survival,” he says.
That’s the main reason the Cincinnati team wants to develop synthetic vernix, but it will not be an easy task. The team has four patents on vernix and its composition, including one for a synthetic version, and has identified many of the key ingredients. But the most challenging phase of mixing everything together and testing the concoctions is still to come. A key goal is finding some kind of molecular structure that can behave like corneocytes. This will be essential to developing a true mimic of vernix that can pack an equally a high content of water.
But the Cincinnati team is not the first to come up with the idea of copying nature’s skin cream. A Canadian company called ProMetic claimed in 1998 to have made a product “designed to replicate the properties of vernix”. It has even trademarked it Vernix. Its chief executive, Pierre Laurin, says it is made up of a mixture of fats and fat-like molecules such as squalenes mixed in the ratios present in vernix. He says the cream has very powerful anti-inflammatory properties and that people who buy it from the company’s website, many of whom have psoriasis, “swear by it”. In ProMetic’s long-term plans, however, the cream is a sideline and its current goal is to isolate the component responsible for its anti-inflammatory properties, Laurin says.
He praises Visscher’s work as “fascinating”, but suspects that her team will hit problems when they try to take synthetic vernix from the lab to the clinic. The US Food and Drug Administration, along with regulatory agencies elsewhere, tends to frown on multi-component therapeutics and encourage single-compound drugs, because it is easier to identify and test the active ingredient.
Visscher accepts that this is a valid concern, and says her team decided from the start to only use materials that had been fully characterised, or had a good safety pedigree, in synthetic vernix. “We’re optimistic this is not an insurmountable issue,” she says. Perhaps it won’t be too long before we all benefit from the secrets of baby-soft skin.