As people age, some joke that their worn, torn bodies are held together by sealing wax and baling wire. More accurately these days, it's glue.

"Glue" includes a wide range of surgical sealants — superglues, bone cements, polymers, clotting agents and other products that share an important quality: They're applied as liquids, then harden into solids.

They repair brain aneurysms, patch hernias, close C-sections, seal knee replacements, stop NBA players from bleeding so they can return to the game. They replace stitches, staples and bandages, speed operations, ease pain, quicken recovery, shorten hospital stays.

"This field — polymer chemistry — has a huge impact on health care," says Dr. Barry Katzen, medical director of the Baptist Cardiac & Vascular Institute in Kendall. "We always think of big, new mechanical devices in medicine, but simple chemistry is extremely important too."

Some of the substances are based on chemistry, others are made from human and animal materials. Here are some of the glues and how they're used:

Onyx: It's a liquid polymer made by EV3 Corp. of Irvine, Calif. In the container it's about as thick as motor oil; when it comes in contact with blood, it sets into a hard spongy mass.

Used for about six months now, it treats brain aneurysms, which happen when a weakened section of a blood vessel inside the skull bulges out into what looks like a balloon. That's dangerous because if the aneurysm bursts, it causes a potentially fatal stroke.

To repair it, the surgeon inserts a microcatheter through a small slit in the groin and snakes it up the femoral artery and into the brain. Its tiny tube injects Onyx directly into the aneurysm, filling it and hardening to seal it off from the blood vessel.

That prevents rupture, says Dr. Italo Linfante, medical director of the Baptist Cardiac & Vascular Institute.

The old method of treating aneurysms involved brain surgery.

Now, Linfante says, "patients can often be released the next day."

Dermabond. Made by Johnson & Johnson, this tissue adhesive is a medical derivative of the superglue sold in drug stores for home repairs. It's used to close skin cuts in everything from a child's teeter-totter accident to facelifts to cosmetic breast augmentation.

"Its biggest advantage is that it helps avoid stitch marks and scars," says Dr. Blane Shatkin, chief of surgery at Memorial Hospital Pembroke in Pembroke Pines.

It's also used instead of surgical staples, which leave even bigger scars than sutures, and in place of "butterfly bandages," which can cause blistering in allergic patients.