Light-activated nanoparticles could avoid painful eye injections for ‘wet’ macular degeneration

Could intravitreal injections become a thing of the past?
(PHOTO: ZKALILA1998 / WIKIMEDIA COMMONS)

There are two standard treatments for “wet” age-related macular degeneration (AMD), in which abnormal, leaky blood vessels in the back of the eye lead to fluid buildup and vision loss. The first, injection of medication directly into the eye, can be painful and can cause inflammation, infection and detachment of the retina. The second, ablation therapy, uses lasers to destroy the leaky blood vessels. It, too, is unpleasant to undergo, and the lasers can also destroy surrounding healthy tissue, causing further vision loss.

In today’s Nature Communications, the lab of Daniel Kohane, MD, PhD, provides proof-of-concept of a more tolerable alternative: tiny, drug-carrying nanoparticles that can be injected intravenously, but deliver medication only to the eye.

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Two new options for treating esophageal damage in children

Rusty Jennings, MD, and Michael Manfredi, MD (CREDIT: MICHAEL GODERRE)

A child’s esophagus can become damaged through physical trauma or ingestion of toxic chemicals or foreign objects — such as oven and drain cleaners, lye, laundry and dishwasher detergents and batteries. Depending on the substance and the amount ingested, children can develop esophageal strictures (scar tissue that narrows the esophagus) or esophageal perforations (holes in the esophagus). These problems can also be complications of surgery for esophageal atresia, in which a baby is born without part of the esophagus.

Children with esophageal perforations have traditionally been treated with long courses of antibiotics and not eating by mouth. More recently, perforations have been treated with stents, and strictures with a combination of dilation and stenting. But stenting, while it can be effective, requires up to eight weeks of therapy and can have complications such as pain, retching and local pressure necrosis, a type of ulcer that may worsen perforation. Such concerns have led researchers to investigate alternative treatments for perforation and strictures.

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How the antidepressant ketamine rapidly awakens the brain, and why its effects vary more in women

(CREDIT: NATHALIE PICARD / BOSTON CHILDREN’S HOSPITAL)

In small doses, the anesthetic ketamine is a mildly hallucinogenic party drug known as “Special K.” In even smaller doses, ketamine relieves depression — abruptly and sometimes dramatically, steering some people away from suicidal thoughts. Studies indicate that ketamine works in 60 to 70 percent of people not helped by slower-acting SSRIs, the usual drugs for depression.

Two ketamine-like drugs are in the clinical pipeline, and, as of this week, one appears close to FDA approval. With no significant new antidepressant in more than 30 years, anticipation is high. Yet no one has pinned down how low-dose ketamine works. Studies have implicated various brain neurotransmitters and their receptors — serotonin, dopamine, glutamate, GABA receptors, opioid receptors — but findings have been contradictory.

“We felt it was time to figure this out once and for all,” says neuroscientist Takao Hensch, PhD.

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Blood stem cell transplants from any donor, without toxicity?

could stem cell transplants be made nontoxic?
(ADOBE STOCK)

Many blood disorders, immune disorders and metabolic disorders can be cured with a transplant of hematopoietic (blood-forming) stem cells, also known as bone marrow transplant. But patients must first receive high-dose, whole-body chemotherapy and/or radiation to deplete their own defective stem cells, providing space for the donor cells to engraft. These “conditioning” regimens are highly toxic: they wipe out the immune system, raising infection risk, and can cause anemia, infertility, other organ damage and cancers. And when the donor isn’t an exact match, patients’ immune systems must be suppressed for prolonged periods to prevent rejection.

As a result, most patients either don’t receive a transplant or must endure serious side effects. But if two new studies bear out in clinical trials, a far gentler conditioning treatment could enable stem-cell transplants for a much wider range of disorders, even possibly from unmatched donors.

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Can we mass-produce platelets in the lab?

Lab-grown platelets could someday be given to patients
Activated platelets (IMAGE: ADOBE STOCK)

Most of us have somewhere around a trillion tiny platelets zooming around our bloodstreams. Joseph Italiano, PhD, of Boston Children’s Hospital’s Vascular Biology Program, calls them the “Swiss Army knives of the blood.” In addition to their key role in clotting, platelets are important in immunity, wound healing, chemical delivery, blood vessel development and more.

At healthcare facilities, platelets are in constant demand for patients with blood diseases, or those receiving radiation or chemotherapy for cancer. But unlike other blood products, platelets can’t be stored for more than a few days. If there’s a snowstorm or other emergency preventing donors from giving platelets, a hospital can easily run out. So researchers have been trying to make platelets in a lab setting.

Two teams at Boston Children’s Hospital are tackling the problem in slightly different ways.

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Natural killer cells: A new angle on neuropathic pain

natural killer cells, peripheral nerve damage and neuropathic pain
Like an immune cleanup crew, natural killer cells (green) infiltrate a damaged axon. (IMAGE: ALEXANDER DAVIES / SEOUL NATIONAL UNIVERSITY AND UNIVERSITY OF OXFORD)

Scientists have known since the 1800s what happens to a totally crushed peripheral nerve in animals: the damaged axons are broken down in a process called Wallerian degeneration, allowing healthy ones to regrow. But humans rarely suffer complete axonal damage. Instead, axons tend to be partially damaged, causing neuropathic pain — a difficult-to-treat, chronic pain associated with nerve trauma, chemotherapy and diabetes.

The lab of Michael Costigan, PhD, in Boston Children’s Hospital’s F.M. Kirby Neurobiology Center is studying how the body’s immune system breaks down these damaged nerves. Their latest research, published today in Cell, may change our understanding of neuropathic pain and how to treat it.

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Gene panel helps investigate sudden unexpected death in children

Thousands of cases of sudden unexplaied death (SUDP) occur each year.
(PHOTO: ADOBESTOCK)

Almost 10 percent of pediatric deaths occur suddenly and without explanation. In this terrible situation, the first question many parents have is “Why?” For most, answers never come.

Childhood deaths that cannot be explained by traditional autopsy and death-scene investigation are referred to as sudden unexplained deaths in pediatrics (SUDP). In children, these deaths are more common than those from either cardiac disease or cancer and typically occur in infancy or early childhood.

Robert’s Program at Boston Children’s Hospital, co-founded by Richard Goldstein, MD, and Hannah Kinney, MD, is adding a genetic approach to the search for answers.

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Drug repurposing and DNA mining: The hunt for new endometriosis treatments

endometriosis researchers Michael Rogers and Danielle Peterse
Michael Rogers and Daniëlle Peterse (PHOTO: MICHAEL GODERRE/BOSTON CHILDREN’S HOSPITAL)

Endometriosis is a common gynecological condition that may affect more than 1 in 10 reproductive-age women. Yet, there’s very little research into the disease and limited options for treatment. A team in the Vascular Biology Program at Boston Children’s Hospital is trying to change that.

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New technique images whole brains with incredible resolution

Overview of brain structures captured by new imaging technique
Combined expansion microscopy and lattice light-sheet microscopy allows for highly detailed images to be taken over large sections of the brain. (IMAGES COURTESY SRIGOKUL UPADHYAYULA, RUIXUAN GAO, AND SHOH ASANO)

Decades ago, discoveries about the brain’s intricate anatomy were made with careful dissection and drawings. Today, they’re made with super-resolution imaging and massive computing power capable of handling hundreds of terabytes of data.

In this week’s Science, a team out of the Massachusetts Institute of Technology (MIT), the Janelia Research Campus of the Howard Hughes Medical Institute (HHMI), Harvard Medical School (HMS) and Boston Children’s Hospital, describes a technique capable of imaging whole brains at exquisitely high resolution, allowing scientists to distinguish tiny sub-cellular structures.

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Children raised in institutions have impaired memory and executive functioning at age 16

long-term effects of child institutionalization

An estimated 8 million children worldwide live in institutions where they experience neglect and deprivation. Last fall, a study of children reared in Romanian orphanages reported high levels of mental health problems when they reached adolescence. In particular, they had more difficult behaviors such as rule-breaking, excessive arguing with authority figures, stealing or assaulting peers. But if they were placed early with carefully vetted foster families through the Bucharest Early Intervention Project (BEIP) , these problems were reduced.

A new BEIP study, published yesterday in the Proceedings of the National Academy of Sciences, examined cognitive functioning. It found that institutionalized children, at ages 8 and 16, also have impaired memory and executive functioning compared with peers placed early in foster homes.

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